datetime — Basic date and time types
Source code:
———
The datetime module supplies classes for manipulating dates and times.
While date and time arithmetic is supported, the focus of the implementation is on efficient attribute extraction for output formatting and manipulation.
Tip
Skip to
.
See also
Module
General calendar related functions.
Module
Time access and conversions.
Module
Concrete time zones representing the IANA time zone database.
Package
Third-party library with expanded time zone and parsing support.
Package
Third-party library that introduces distinct static types to for example, allow
to differentiate between naive and aware datetimes.
Aware and naive objects
Date and time objects may be categorized as “aware” or “naive” depending on whether or not they include time zone information.
With sufficient knowledge of applicable algorithmic and political time adjustments, such as time zone and daylight saving time information, an aware object can locate itself relative to other aware objects. An aware object represents a specific moment in time that is not open to interpretation.
A naive object does not contain enough information to unambiguously locate itself relative to other date/time objects. Whether a naive object represents Coordinated Universal Time (UTC), local time, or time in some other time zone is purely up to the program, just like it is up to the program whether a particular number represents metres, miles, or mass. Naive objects are easy to understand and to work with, at the cost of ignoring some aspects of reality.
For applications requiring aware objects,
and
objects have an optional time zone information attribute, tzinfo, that can be set to an instance of a subclass of the abstract tzinfo class. These
objects capture information about the offset from UTC time, the time zone name, and whether daylight saving time is in effect.
Only one concrete
class, the
class, is supplied by the datetime module. The timezone class can represent simple time zones with fixed offsets from UTC, such as UTC itself or North American EST and EDT time zones. Supporting time zones at deeper levels of detail is up to the application. The rules for time adjustment across the world are more political than rational, change frequently, and there is no standard suitable for every application aside from UTC.
Constants
The datetime module exports the following constants:
datetime.MINYEAR
The smallest year number allowed in a
or
object.
is 1.
datetime.MAXYEAR
The largest year number allowed in a
or
object.
is 9999.
datetime.UTC
Alias for the UTC time zone singleton
.
Added in version 3.11.
Available types
classdatetime.dateAn idealized naive date, assuming the current Gregorian calendar always was, and always will be, in effect. Attributes:
,
, and
.
classdatetime.timeAn idealized time, independent of any particular day, assuming that every day has exactly 24*60*60 seconds. (There is no notion of “leap seconds” here.) Attributes:
,
,
,
, and
.
classdatetime.datetimeA combination of a date and a time. Attributes:
,
,
,
,
,
,
, and
.
classdatetime.timedeltaA duration expressing the difference between two
or
instances to microsecond resolution.
classdatetime.tzinfoAn abstract base class for time zone information objects. These are used by the
and
classes to provide a customizable notion of time adjustment (for example, to account for time zone and/or daylight saving time).
classdatetime.timezoneA class that implements the
abstract base class as a fixed offset from the UTC.
Added in version 3.2.
Objects of these types are immutable.
Subclass relationships:
Common properties
The
,
,
, and
types share these common features:
Objects of these types are immutable.
Objects of these types are
, meaning that they can be used as dictionary keys.
Objects of these types support efficient pickling via the
module.
Determining if an object is aware or naive
Objects of the
type are always naive.
An object of type
or
may be aware or naive.
A
object d is aware if both of the following hold:
d.tzinfo is not None
d.tzinfo.utcoffset(d) does not return None
Otherwise, d is naive.
A
object t is aware if both of the following hold:
t.tzinfo is not None
t.tzinfo.utcoffset(None) does not return None.
Otherwise, t is naive.
The distinction between aware and naive doesn’t apply to
objects.
timedelta objects
A
object represents a duration, the difference between two
or
instances.
classdatetime.timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)
All arguments are optional and default to 0. Arguments may be integers or floats, and may be positive or negative.
Only days, seconds and microseconds are stored internally. Arguments are converted to those units:
A millisecond is converted to 1000 microseconds.
A minute is converted to 60 seconds.
An hour is converted to 3600 seconds.
A week is converted to 7 days.
and days, seconds and microseconds are then normalized so that the representation is unique, with
0<=microseconds<1000000
0<=seconds<3600*24 (the number of seconds in one day)
-999999999<=days<=999999999
The following example illustrates how any arguments besides days, seconds and microseconds are “merged” and normalized into those three resulting attributes:
>>> importdatetimeasdt>>> delta=dt.timedelta(... days=50,... seconds=27,... microseconds=10,... milliseconds=29000,... minutes=5,... hours=8,... weeks=2... )>>> # Only days, seconds, and microseconds remain>>> deltadatetime.timedelta(days=64, seconds=29156, microseconds=10)If any argument is a float and there are fractional microseconds, the fractional microseconds left over from all arguments are combined and their sum is rounded to the nearest microsecond using round-half-to-even tiebreaker. If no argument is a float, the conversion and normalization processes are exact (no information is lost).
If the normalized value of days lies outside the indicated range,
is raised.
Note that normalization of negative values may be surprising at first. For example:
>>> importdatetimeasdt>>> d=dt.timedelta(microseconds=-1)>>> (d.days,d.seconds,d.microseconds)(-1, 86399, 999999)Since the string representation of timedelta objects can be confusing, use the following recipe to produce a more readable format:
>>> defpretty_timedelta(td):... iftd.days>=0:... returnstr(td)... returnf'-({-td!s})'...>>> d=timedelta(hours=-1)>>> str(d)# not human-friendly'-1 day, 23:00:00'>>> pretty_timedelta(d)'-(1:00:00)'Class attributes:
timedelta.min
The most negative
object, timedelta(-999999999).
timedelta.max
The most positive
object, timedelta(days=999999999,hours=23,minutes=59,seconds=59,microseconds=999999).
timedelta.resolution
The smallest possible difference between non-equal
objects, timedelta(microseconds=1).
Note that, because of normalization, timedelta.max is greater than -timedelta.min. -timedelta.max is not representable as a
object.
Instance attributes (read-only):
timedelta.days
Between -999,999,999 and 999,999,999 inclusive.
timedelta.seconds
Between 0 and 86,399 inclusive.
Caution
It is a somewhat common bug for code to unintentionally use this attribute when it is actually intended to get a
value instead:
>>> importdatetimeasdt>>> duration=dt.timedelta(seconds=11235813)>>> duration.days,duration.seconds(130, 3813)>>> duration.total_seconds()11235813.0timedelta.microseconds
Between 0 and 999,999 inclusive.
Supported operations:
Operation
Result
t1=t2+t3
Sum of t2 and t3. Afterwards t1-t2==t3 and t1-t3==t2 are true. (1)
t1=t2-t3
Difference of t2 and t3. Afterwards t1==t2-t3 and t2==t1+t3 are true. (1)(6)
t1=t2*iort1=i*t2
Delta multiplied by an integer. Afterwards t1//i==t2 is true, provided i!=0.
In general, t1*i==t1*(i-1)+t1 is true. (1)
t1=t2*fort1=f*t2
Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
f=t2/t3
Division (3) of overall duration t2 by interval unit t3. Returns a
object.
t1=t2/fort1=t2/i
Delta divided by a float or an int. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
t1=t2//i or t1=t2//t3
The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)
t1=t2%t3
The remainder is computed as a
object. (3)
q,r=divmod(t1,t2)
Computes the quotient and the remainder: q=t1//t2 (3) and r=t1%t2. q is an integer and r is a
object.
+t1
Returns a
object with the same value. (2)
-t1
Equivalent to timedelta(-t1.days,-t1.seconds,-t1.microseconds), and to t1*-1. (1)(4)
abs(t)
Equivalent to +t when t.days>=0, and to -t when t.days<0. (2)
str(t)
Returns a string in the form [Dday[s],][H]H:MM:SS[.UUUUUU], where D is negative for negative t. (5)
repr(t)
Returns a string representation of the
object as a constructor call with canonical attribute values.
Notes:
This is exact but may overflow.
This is exact and cannot overflow.
Division by zero raises
.
-timedelta.max is not representable as a
object.
String representations of
objects are normalized similarly to their internal representation. This leads to somewhat unusual results for negative timedeltas. For example:
>>> timedelta(hours=-5)datetime.timedelta(days=-1, seconds=68400)>>> print(_)-1 day, 19:00:00
The expression t2-t3 will always be equal to the expression t2+(-t3) except when t3 is equal to timedelta.max; in that case the former will produce a result while the latter will overflow.
In addition to the operations listed above,
objects support certain additions and subtractions with
and
objects (see below).
Changed in version 3.2: Floor division and true division of a
object by another timedelta object are now supported, as are remainder operations and the
function. True division and multiplication of a timedelta object by a
object are now supported.
objects support equality and order comparisons.
In Boolean contexts, a
object is considered to be true if and only if it isn’t equal to timedelta(0).
Instance methods:
timedelta.total_seconds()
Return the total number of seconds contained in the duration. Equivalent to td/timedelta(seconds=1). For interval units other than seconds, use the division form directly (for example, td/timedelta(microseconds=1)).
Note that for very large time intervals (greater than 270 years on most platforms) this method will lose microsecond accuracy.
Added in version 3.2.
Examples of usage: timedelta
An additional example of normalization:
>>> # Components of another_year add up to exactly 365 days>>> importdatetimeasdt>>> year=dt.timedelta(days=365)>>> another_year=dt.timedelta(weeks=40,days=84,hours=23,... minutes=50,seconds=600)>>> year==another_yearTrue>>> year.total_seconds()31536000.0Examples of
arithmetic:
>>> importdatetimeasdt>>> year=dt.timedelta(days=365)>>> ten_years=10*year>>> ten_yearsdatetime.timedelta(days=3650)>>> ten_years.days//36510>>> nine_years=ten_years-year>>> nine_yearsdatetime.timedelta(days=3285)>>> three_years=nine_years//3>>> three_years,three_years.days//365(datetime.timedelta(days=1095), 3)date objects
A
object represents a date (year, month and day) in an idealized calendar, the current Gregorian calendar indefinitely extended in both directions.
January 1 of year 1 is called day number 1, January 2 of year 1 is called day number 2, and so on.
classdatetime.date(year, month, day)
All arguments are required. Arguments must be integers, in the following ranges:
MINYEAR<=year<=MAXYEAR
1<=month<=12
1<=day<=numberofdaysinthegivenmonthandyear
If an argument outside those ranges is given,
is raised.
Other constructors, all class methods:
classmethoddate.today()
Return the current local date.
This is equivalent to date.fromtimestamp(time.time()).
classmethoddate.fromtimestamp(timestamp)
Return the local date corresponding to the POSIX timestamp, such as is returned by
.
This may raise
, if the timestamp is out of the range of values supported by the platform C localtime() function, and
on localtime() failure. It’s common for this to be restricted to years from 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp().
Changed in version 3.3: Raise
instead of
if the timestamp is out of the range of values supported by the platform C localtime() function. Raise
instead of ValueError on localtime() failure.
classmethoddate.fromordinal(ordinal)
Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.
is raised unless 1<=ordinal<=date.max.toordinal(). For any date d, date.fromordinal(d.toordinal())==d.
classmethoddate.fromisoformat(date_string)
Return a
corresponding to a date_string given in any valid ISO 8601 format, with the following exceptions:
Reduced precision dates are not currently supported (YYYY-MM, YYYY).
Extended date representations are not currently supported (±YYYYYY-MM-DD).
Ordinal dates are not currently supported (YYYY-OOO).
Examples:
>>> importdatetimeasdt>>> dt.date.fromisoformat('2019-12-04')datetime.date(2019, 12, 4)>>> dt.date.fromisoformat('20191204')datetime.date(2019, 12, 4)>>> dt.date.fromisoformat('2021-W01-1')datetime.date(2021, 1, 4)Added in version 3.7.
Changed in version 3.11: Previously, this method only supported the format YYYY-MM-DD.
classmethoddate.fromisocalendar(year, week, day)
Return a
corresponding to the ISO calendar date specified by year, week and day. This is the inverse of the function
.
Added in version 3.8.
classmethoddate.strptime(date_string, format)
Return a
corresponding to date_string, parsed according to format. This is equivalent to:
date(*(time.strptime(date_string,format)[0:3]))
is raised if the date_string and format can’t be parsed by
or if it returns a value which isn’t a time tuple. See also
strftime() and strptime() behavior
and
.
Note
If format specifies a day of month without a year a
is emitted. This is to avoid a quadrennial leap year bug in code seeking to parse only a month and day as the default year used in absence of one in the format is not a leap year. Such format values may raise an error as of Python 3.15. The workaround is to always include a year in your format. If parsing date_string values that do not have a year, explicitly add a year that is a leap year before parsing:
>>> importdatetimeasdt>>> date_string="02/29">>> when=dt.date.strptime(f"{date_string};1984","%m/%d;%Y")# Avoids leap year bug.>>> when.strftime("%B %d")'February 29'Added in version 3.14.
Class attributes:
date.min
The earliest representable date, date(MINYEAR,1,1).
date.max
The latest representable date, date(MAXYEAR,12,31).
date.resolution
The smallest possible difference between non-equal date objects, timedelta(days=1).
Instance attributes (read-only):
date.year
Between
and
inclusive.
date.month
Between 1 and 12 inclusive.
date.day
Between 1 and the number of days in the given month of the given year.
Supported operations:
Operation
Result
date2=date1+timedelta
date2 will be timedelta.days days after date1. (1)
date2=date1-timedelta
Computes date2 such that date2+timedelta==date1. (2)
timedelta=date1-date2
(3)
date1==date2
date1!=date2
Equality comparison. (4)
date1<date2
date1>date2
date1<=date2
date1>=date2
Order comparison. (5)
Notes:
date2 is moved forward in time if timedelta.days>0, or backward if timedelta.days<0. Afterward date2-date1==timedelta.days. timedelta.seconds and timedelta.microseconds are ignored.
is raised if date2.year would be smaller than
or larger than
.
timedelta.seconds and timedelta.microseconds are ignored.
This is exact, and cannot overflow. timedelta.seconds and timedelta.microseconds are 0, and date2+timedelta==date1 after.
objects are equal if they represent the same date.
date objects that are not also
instances are never equal to datetime objects, even if they represent the same date.
date1 is considered less than date2 when date1 precedes date2 in time. In other words, date1<date2 if and only if date1.toordinal()<date2.toordinal().
Order comparison between a
object that is not also a
instance and a datetime object raises
.
Changed in version 3.13: Comparison between
object and an instance of the
subclass that is not a datetime subclass no longer converts the latter to date, ignoring the time part and the time zone. The default behavior can be changed by overriding the special comparison methods in subclasses.
In Boolean contexts, all
objects are considered to be true.
Instance methods:
date.replace(year=self.year, month=self.month, day=self.day)
Return a new
object with the same values, but with specified parameters updated.
Example:
>>> importdatetimeasdt>>> d=dt.date(2002,12,31)>>> d.replace(day=26)datetime.date(2002, 12, 26)The generic function
also supports
objects.
date.timetuple()
Return a
such as returned by
.
The hours, minutes and seconds are 0, and the DST flag is -1.
d.timetuple() is equivalent to:
time.struct_time((d.year,d.month,d.day,0,0,0,d.weekday(),yday,-1))where yday=d.toordinal()-date(d.year,1,1).toordinal()+1 is the day number within the current year starting with 1 for January 1st.
date.toordinal()
Return the proleptic Gregorian ordinal of the date, where January 1 of year 1 has ordinal 1. For any
object d, date.fromordinal(d.toordinal())==d.
date.weekday()
Return the day of the week as an integer, where Monday is 0 and Sunday is 6. For example, date(2002,12,4).weekday()==2, a Wednesday. See also
.
date.isoweekday()
Return the day of the week as an integer, where Monday is 1 and Sunday is 7. For example, date(2002,12,4).isoweekday()==3, a Wednesday. See also
,
.
date.isocalendar()
Return a
object with three components: year, week and weekday.
The ISO calendar is a widely used variant of the Gregorian calendar.
The ISO year consists of 52 or 53 full weeks, and where a week starts on a Monday and ends on a Sunday. The first week of an ISO year is the first (Gregorian) calendar week of a year containing a Thursday. This is called week number 1, and the ISO year of that Thursday is the same as its Gregorian year.
For example, 2004 begins on a Thursday, so the first week of ISO year 2004 begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan 2004:
>>> importdatetimeasdt>>> dt.date(2003,12,29).isocalendar()datetime.IsoCalendarDate(year=2004, week=1, weekday=1)>>> dt.date(2004,1,4).isocalendar()datetime.IsoCalendarDate(year=2004, week=1, weekday=7)Changed in version 3.9: Result changed from a tuple to a
.
date.isoformat()
Return a string representing the date in ISO 8601 format, YYYY-MM-DD:
>>> importdatetimeasdt>>> dt.date(2002,12,4).isoformat()'2002-12-04'date.__str__()
For a date d, str(d) is equivalent to d.isoformat().
date.ctime()
Return a string representing the date:
>>> importdatetimeasdt>>> dt.date(2002,12,4).ctime()'Wed Dec 4 00:00:00 2002'd.ctime() is equivalent to:
time.ctime(time.mktime(d.timetuple()))on platforms where the native C ctime() function (which
invokes, but which date.ctime() does not invoke) conforms to the C standard.
date.strftime(format)
Return a string representing the date, controlled by an explicit format string. Format codes referring to hours, minutes or seconds will see 0 values. See also
strftime() and strptime() behavior
and
.
date.__format__(format)
Same as
. This makes it possible to specify a format string for a
object in
and when using
. See also
strftime() and strptime() behavior
and
.
Examples of usage: date
Example of counting days to an event:
>>> importtime>>> importdatetimeasdt>>> today=dt.date.today()>>> todaydatetime.date(2007, 12, 5)>>> today==dt.date.fromtimestamp(time.time())True>>> my_birthday=dt.date(today.year,6,24)>>> ifmy_birthday<today:... my_birthday=my_birthday.replace(year=today.year+1)...>>> my_birthdaydatetime.date(2008, 6, 24)>>> time_to_birthday=abs(my_birthday-today)>>> time_to_birthday.days202More examples of working with
:
>>> importdatetimeasdt>>> d=dt.date.fromordinal(730920)# 730920th day after 1. 1. 0001>>> ddatetime.date(2002, 3, 11)>>> # Methods related to formatting string output>>> d.isoformat()'2002-03-11'>>> d.strftime("%d/%m/%y")'11/03/02'>>> d.strftime("%A %d. %B %Y")'Monday 11. March 2002'>>> d.ctime()'Mon Mar 11 00:00:00 2002'>>> 'The {1} is {0:%d}, the {2} is {0:%B}.'.format(d,"day","month")'The day is 11, the month is March.'>>> # Methods for extracting 'components' under different calendars>>> t=d.timetuple()>>> foriint:... print(i)2002 # year3 # month11 # day0000 # weekday (0 = Monday)70 # 70th day in the year-1>>> ic=d.isocalendar()>>> foriinic:... print(i)2002 # ISO year11 # ISO week number1 # ISO day number ( 1 = Monday )>>> # A date object is immutable; all operations produce a new object>>> d.replace(year=2005)datetime.date(2005, 3, 11)datetime objects
A
object is a single object containing all the information from a
object and a
object.
Like a
object,
assumes the current Gregorian calendar extended in both directions; like a
object, datetime assumes there are exactly 3600*24 seconds in every day.
Constructor:
classdatetime.datetime(year, month, day, hour=0, minute=0, second=0, microsecond=0, tzinfo=None, *, fold=0)
The year, month and day arguments are required. tzinfo may be None, or an instance of a
subclass. The remaining arguments must be integers in the following ranges:
MINYEAR<=year<=MAXYEAR,
1<=month<=12,
1<=day<=numberofdaysinthegivenmonthandyear,
0<=hour<24,
0<=minute<60,
0<=second<60,
0<=microsecond<1000000,
foldin[0,1].
If an argument outside those ranges is given,
is raised.
Changed in version 3.6: Added the fold parameter.
Other constructors, all class methods:
classmethoddatetime.today()
Return the current local date and time, with
None.
Equivalent to:
datetime.fromtimestamp(time.time())See also
,
.
This method is functionally equivalent to
, but without a tz parameter.
classmethoddatetime.now(tz=None)
Return the current local date and time.
If optional argument tz is None or not specified, this is like
, but, if possible, supplies more precision than can be gotten from going through a
timestamp (for example, this may be possible on platforms supplying the C gettimeofday() function).
If tz is not None, it must be an instance of a
subclass, and the current date and time are converted to tz’s time zone.
This function is preferred over
and
.
Note
Subsequent calls to datetime.now() may return the same instant depending on the precision of the underlying clock.
classmethoddatetime.utcnow()
Return the current UTC date and time, with
None.
This is like
, but returns the current UTC date and time, as a naive
object. An aware current UTC datetime can be obtained by calling datetime.now(timezone.utc). See also now().
Warning
Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing the current time in UTC is by calling datetime.now(timezone.utc).
Deprecated since version 3.12: Use
with
instead.
classmethoddatetime.fromtimestamp(timestamp, tz=None)
Return the local date and time corresponding to the POSIX timestamp, such as is returned by
. If optional argument tz is None or not specified, the timestamp is converted to the platform’s local date and time, and the returned
object is naive.
If tz is not None, it must be an instance of a
subclass, and the timestamp is converted to tz’s time zone.
fromtimestamp() may raise
, if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions, and
on localtime() or gmtime() failure. It’s common for this to be restricted to years in 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp(), and then it’s possible to have two timestamps differing by a second that yield identical
objects. This method is preferred over
.
Changed in version 3.3: Raise
instead of
if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions. Raise
instead of ValueError on localtime() or gmtime() failure.
Changed in version 3.6: fromtimestamp() may return instances with
set to 1.
classmethoddatetime.utcfromtimestamp(timestamp)
Return the UTC
corresponding to the POSIX timestamp, with
None. (The resulting object is naive.)
This may raise
, if the timestamp is out of the range of values supported by the platform C gmtime() function, and
on gmtime() failure. It’s common for this to be restricted to years in 1970 through 2038.
To get an aware
object, call
:
datetime.fromtimestamp(timestamp,timezone.utc)On the POSIX compliant platforms, it is equivalent to the following expression:
datetime(1970,1,1,tzinfo=timezone.utc)+timedelta(seconds=timestamp)except the latter formula always supports the full years range: between
and
inclusive.
Warning
Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing a specific timestamp in UTC is by calling datetime.fromtimestamp(timestamp,tz=timezone.utc).
Changed in version 3.3: Raise
instead of
if the timestamp is out of the range of values supported by the platform C gmtime() function. Raise
instead of ValueError on gmtime() failure.
Changed in version 3.15: Accepts any real number as timestamp, not only integer or float.
Deprecated since version 3.12: Use
with
instead.
classmethoddatetime.fromordinal(ordinal)
Return the
corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.
is raised unless 1<=ordinal<=datetime.max.toordinal(). The hour, minute, second and microsecond of the result are all 0, and
is None.
classmethoddatetime.combine(date, time, tzinfo=time.tzinfo)
Return a new
object whose date components are equal to the given
object’s, and whose time components are equal to the given
object’s. If the tzinfo argument is provided, its value is used to set the
attribute of the result, otherwise the
attribute of the time argument is used. If the date argument is a datetime object, its time components and tzinfo attributes are ignored.
For any
object d, d==datetime.combine(d.date(),d.time(),d.tzinfo).
Changed in version 3.6: Added the tzinfo argument.
classmethoddatetime.fromisoformat(date_string)
Return a
corresponding to a date_string in any valid ISO 8601 format, with the following exceptions:
Time zone offsets may have fractional seconds.
The T separator may be replaced by any single unicode character.
Fractional hours and minutes are not supported.
Reduced precision dates are not currently supported (YYYY-MM, YYYY).
Extended date representations are not currently supported (±YYYYYY-MM-DD).
Ordinal dates are not currently supported (YYYY-OOO).
Examples:
>>> importdatetimeasdt>>> dt.datetime.fromisoformat('2011-11-04')datetime.datetime(2011, 11, 4, 0, 0)>>> dt.datetime.fromisoformat('20111104')datetime.datetime(2011, 11, 4, 0, 0)>>> dt.datetime.fromisoformat('2011-11-04T00:05:23')datetime.datetime(2011, 11, 4, 0, 5, 23)>>> dt.datetime.fromisoformat('2011-11-04T00:05:23Z')datetime.datetime(2011, 11, 4, 0, 5, 23, tzinfo=datetime.timezone.utc)>>> dt.datetime.fromisoformat('20111104T000523')datetime.datetime(2011, 11, 4, 0, 5, 23)>>> dt.datetime.fromisoformat('2011-W01-2T00:05:23.283')datetime.datetime(2011, 1, 4, 0, 5, 23, 283000)>>> dt.datetime.fromisoformat('2011-11-04 00:05:23.283')datetime.datetime(2011, 11, 4, 0, 5, 23, 283000)>>> dt.datetime.fromisoformat('2011-11-04 00:05:23.283+00:00')datetime.datetime(2011, 11, 4, 0, 5, 23, 283000, tzinfo=datetime.timezone.utc)>>> dt.datetime.fromisoformat('2011-11-04T00:05:23+04:00')datetime.datetime(2011, 11, 4, 0, 5, 23, tzinfo=datetime.timezone(datetime.timedelta(seconds=14400)))Added in version 3.7.
Changed in version 3.11: Previously, this method only supported formats that could be emitted by
or
.
classmethoddatetime.fromisocalendar(year, week, day)
Return a
corresponding to the ISO calendar date specified by year, week and day. The non-date components of the datetime are populated with their normal default values. This is the inverse of the function
.
Added in version 3.8.
classmethoddatetime.strptime(date_string, format)
Return a
corresponding to date_string, parsed according to format.
If format does not contain microseconds or time zone information, this is equivalent to:
datetime(*(time.strptime(date_string,format)[0:6]))
is raised if the date_string and format can’t be parsed by
or if it returns a value which isn’t a time tuple. See also
strftime() and strptime() behavior
and
.
Changed in version 3.13: If format specifies a day of month without a year a
is now emitted. This is to avoid a quadrennial leap year bug in code seeking to parse only a month and day as the default year used in absence of one in the format is not a leap year. Such format values may raise an error as of Python 3.15. The workaround is to always include a year in your format. If parsing date_string values that do not have a year, explicitly add a year that is a leap year before parsing:
>>> importdatetimeasdt>>> date_string="02/29">>> when=dt.datetime.strptime(f"{date_string};1984","%m/%d;%Y")# Avoids leap year bug.>>> when.strftime("%B %d")'February 29'Class attributes:
datetime.min
The earliest representable
, datetime(MINYEAR,1,1,tzinfo=None).
datetime.max
The latest representable
, datetime(MAXYEAR,12,31,23,59,59,999999,tzinfo=None).
datetime.resolution
The smallest possible difference between non-equal
objects, timedelta(microseconds=1).
Instance attributes (read-only):
datetime.year
Between
and
inclusive.
datetime.month
Between 1 and 12 inclusive.
datetime.day
Between 1 and the number of days in the given month of the given year.
datetime.hour
In range(24).
datetime.minute
In range(60).
datetime.second
In range(60).
datetime.microsecond
In range(1000000).
datetime.tzinfo
The object passed as the tzinfo argument to the
constructor, or None if none was passed.
datetime.fold
In [0,1]. Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The values 0 and 1 represent, respectively, the earlier and later of the two moments with the same wall time representation.
Added in version 3.6.
Supported operations:
Operation
Result
datetime2=datetime1+timedelta
(1)
datetime2=datetime1-timedelta
(2)
timedelta=datetime1-datetime2
(3)
datetime1==datetime2
datetime1!=datetime2
Equality comparison. (4)
datetime1<datetime2
datetime1>datetime2
datetime1<=datetime2
datetime1>=datetime2
Order comparison. (5)
datetime2 is a duration of timedelta removed from datetime1, moving forward in time if timedelta.days>0, or backward if timedelta.days<0. The result has the same
attribute as the input datetime, and datetime2-datetime1==timedelta after.
is raised if datetime2.year would be smaller than
or larger than
. Note that no time zone adjustments are done even if the input is an aware object.
Computes the datetime2 such that datetime2+timedelta==datetime1. As for addition, the result has the same
attribute as the input datetime, and no time zone adjustments are done even if the input is aware.
Subtraction of a
from a datetime is defined only if both operands are naive, or if both are aware. If one is aware and the other is naive,
is raised.
If both are naive, or both are aware and have the same
attribute, the tzinfo attributes are ignored, and the result is a
object t such that datetime2+t==datetime1. No time zone adjustments are done in this case.
If both are aware and have different
attributes, a-b acts as if a and b were first converted to naive UTC datetimes. The result is (a.replace(tzinfo=None)-a.utcoffset())-(b.replace(tzinfo=None)-b.utcoffset()) except that the implementation never overflows.
objects are equal if they represent the same date and time, taking into account the time zone.
Naive and aware
objects are never equal.
If both comparands are aware, and have the same tzinfo attribute, the tzinfo and
attributes are ignored and the base datetimes are compared. If both comparands are aware and have different
attributes, the comparison acts as comparands were first converted to UTC datetimes except that the implementation never overflows.
instances in a repeated interval are never equal to datetime instances in other time zone.
datetime1 is considered less than datetime2 when datetime1 precedes datetime2 in time, taking into account the time zone.
Order comparison between naive and aware
objects raises
.
If both comparands are aware, and have the same tzinfo attribute, the tzinfo and
attributes are ignored and the base datetimes are compared. If both comparands are aware and have different
attributes, the comparison acts as comparands were first converted to UTC datetimes except that the implementation never overflows.
Changed in version 3.3: Equality comparisons between aware and naive
instances don’t raise
.
Changed in version 3.13: Comparison between
object and an instance of the
subclass that is not a datetime subclass no longer converts the latter to date, ignoring the time part and the time zone. The default behavior can be changed by overriding the special comparison methods in subclasses.
Instance methods:
datetime.date()
Return
object with same year, month and day.
datetime.time()
Return
object with same hour, minute, second, microsecond and fold.
is None. See also method
.
Changed in version 3.6: The fold value is copied to the returned
object.
datetime.timetz()
Return
object with same hour, minute, second, microsecond, fold, and tzinfo attributes. See also method
.
Changed in version 3.6: The fold value is copied to the returned
object.
datetime.replace(year=self.year, month=self.month, day=self.day, hour=self.hour, minute=self.minute, second=self.second, microsecond=self.microsecond, tzinfo=self.tzinfo, *, fold=0)
Return a new
object with the same attributes, but with specified parameters updated. Note that tzinfo=None can be specified to create a naive datetime from an aware datetime with no conversion of date and time data.
objects are also supported by generic function
.
Changed in version 3.6: Added the fold parameter.
datetime.astimezone(tz=None)
Return a
object with new
attribute tz, adjusting the date and time data so the result is the same UTC time as self, but in tz’s local time.
If provided, tz must be an instance of a
subclass, and its
and
methods must not return None. If self is naive, it is presumed to represent time in the system time zone.
If called without arguments (or with tz=None) the system local time zone is assumed for the target time zone. The .tzinfo attribute of the converted datetime instance will be set to an instance of
with the zone name and offset obtained from the OS.
If self.tzinfo is tz, self.astimezone(tz) is equal to self: no adjustment of date or time data is performed. Else the result is local time in the time zone tz, representing the same UTC time as self: after astz=dt.astimezone(tz), astz-astz.utcoffset() will have the same date and time data as dt-dt.utcoffset().
If you merely want to attach a
object tz to a datetime dt without adjustment of date and time data, use dt.replace(tzinfo=tz). If you merely want to remove the timezone object from an aware datetime dt without conversion of date and time data, use dt.replace(tzinfo=None).
Note that the default
method can be overridden in a
subclass to affect the result returned by astimezone(). Ignoring error cases, astimezone() acts like:
defastimezone(self,tz):ifself.tzinfoistz:returnself# Convert self to UTC, and attach the new timezone object.utc=(self-self.utcoffset()).replace(tzinfo=tz)# Convert from UTC to tz's local time.returntz.fromutc(utc)Changed in version 3.3: tz now can be omitted.
Changed in version 3.6: The astimezone() method can now be called on naive instances that are presumed to represent system local time.
datetime.utcoffset()
If
is None, returns None, else returns self.tzinfo.utcoffset(self), and raises an exception if the latter doesn’t return None or a
object with magnitude less than one day.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
datetime.dst()
If
is None, returns None, else returns self.tzinfo.dst(self), and raises an exception if the latter doesn’t return None or a
object with magnitude less than one day.
Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.
datetime.tzname()
If
is None, returns None, else returns self.tzinfo.tzname(self), raises an exception if the latter doesn’t return None or a string object,
datetime.timetuple()
Return a
such as returned by
.
d.timetuple() is equivalent to:
time.struct_time((d.year,d.month,d.day,d.hour,d.minute,d.second,d.weekday(),yday,dst))where yday=d.toordinal()-date(d.year,1,1).toordinal()+1 is the day number within the current year starting with 1 for January 1st. The
flag of the result is set according to the
method:
is None or dst() returns None, tm_isdst is set to -1; else if dst() returns a non-zero value, tm_isdst is set to 1; else tm_isdst is set to 0.
datetime.utctimetuple()
If
instance d is naive, this is the same as d.timetuple() except that
is forced to 0 regardless of what d.dst() returns. DST is never in effect for a UTC time.
If d is aware, d is normalized to UTC time, by subtracting d.utcoffset(), and a
for the normalized time is returned. tm_isdst is forced to 0. Note that an
may be raised if d.year was MINYEAR or MAXYEAR and UTC adjustment spills over a year boundary.
Warning
Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC; as a result, using datetime.utctimetuple() may give misleading results. If you have a naive datetime representing UTC, use datetime.replace(tzinfo=timezone.utc) to make it aware, at which point you can use
.
datetime.toordinal()
Return the proleptic Gregorian ordinal of the date. The same as self.date().toordinal().
datetime.timestamp()
Return POSIX timestamp corresponding to the
instance. The return value is a
similar to that returned by
.
Naive
instances are assumed to represent local time and this method relies on platform C functions to perform the conversion. Since datetime supports a wider range of values than the platform C functions on many platforms, this method may raise
or
for times far in the past or far in the future.
For aware
instances, the return value is computed as:
(dt-datetime(1970,1,1,tzinfo=timezone.utc)).total_seconds()Note
There is no method to obtain the POSIX timestamp directly from a naive
instance representing UTC time. If your application uses this convention and your system time zone is not set to UTC, you can obtain the POSIX timestamp by supplying tzinfo=timezone.utc:
timestamp=dt.replace(tzinfo=timezone.utc).timestamp()or by calculating the timestamp directly:
timestamp=(dt-datetime(1970,1,1))/timedelta(seconds=1)Added in version 3.3.
Changed in version 3.6: The timestamp() method uses the
attribute to disambiguate the times during a repeated interval.
Changed in version 3.6: This method no longer relies on the platform C mktime() function to perform conversions.
datetime.weekday()
Return the day of the week as an integer, where Monday is 0 and Sunday is 6. The same as self.date().weekday(). See also
.
datetime.isoweekday()
Return the day of the week as an integer, where Monday is 1 and Sunday is 7. The same as self.date().isoweekday(). See also
,
.
datetime.isocalendar()
Return a
with three components: year, week and weekday. The same as self.date().isocalendar().
datetime.isoformat(sep='T', timespec='auto')
Return a string representing the date and time in ISO 8601 format:
YYYY-MM-DDTHH:MM:SS.ffffff, if
is not 0
YYYY-MM-DDTHH:MM:SS, if
is 0
If
does not return None, a string is appended, giving the UTC offset:
YYYY-MM-DDTHH:MM:SS.ffffff+HH:MM[:SS[.ffffff]], if
is not 0
YYYY-MM-DDTHH:MM:SS+HH:MM[:SS[.ffffff]], if
is 0
Examples:
>>> importdatetimeasdt>>> dt.datetime(2019,5,18,15,17,8,132263).isoformat()'2019-05-18T15:17:08.132263'>>> dt.datetime(2019,5,18,15,17,tzinfo=dt.timezone.utc).isoformat()'2019-05-18T15:17:00+00:00'The optional argument sep (default 'T') is a one-character separator, placed between the date and time portions of the result. For example:
>>> importdatetimeasdt>>> classTZ(dt.tzinfo):... """A time zone with an arbitrary, constant -06:39 offset."""... defutcoffset(self,when):... returndt.timedelta(hours=-6,minutes=-39)...>>> dt.datetime(2002,12,25,tzinfo=TZ()).isoformat(' ')'2002-12-25 00:00:00-06:39'>>> dt.datetime(2009,11,27,microsecond=100,tzinfo=TZ()).isoformat()'2009-11-27T00:00:00.000100-06:39'The optional argument timespec specifies the number of additional components of the time to include (the default is 'auto'). It can be one of the following:
'auto': Same as 'seconds' if
is 0, same as 'microseconds' otherwise.
'hours': Include the
in the two-digit HH format.
'minutes': Include
and
in HH:MM format.
'seconds': Include
,
, and
in HH:MM:SS format.
'milliseconds': Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.
'microseconds': Include full time in HH:MM:SS.ffffff format.
Note
Excluded time components are truncated, not rounded.
will be raised on an invalid timespec argument:
>>> importdatetimeasdt>>> dt.datetime.now().isoformat(timespec='minutes')'2002-12-25T00:00'>>> my_datetime=dt.datetime(2015,1,1,12,30,59,0)>>> my_datetime.isoformat(timespec='microseconds')'2015-01-01T12:30:59.000000'Changed in version 3.6: Added the timespec parameter.
datetime.__str__()
For a
instance d, str(d) is equivalent to d.isoformat('').
datetime.ctime()
Return a string representing the date and time:
>>> importdatetimeasdt>>> dt.datetime(2002,12,4,20,30,40).ctime()'Wed Dec 4 20:30:40 2002'The output string will not include time zone information, regardless of whether the input is aware or naive.
d.ctime() is equivalent to:
time.ctime(time.mktime(d.timetuple()))on platforms where the native C ctime() function (which
invokes, but which datetime.ctime() does not invoke) conforms to the C standard.
datetime.strftime(format)
Return a string representing the date and time, controlled by an explicit format string. See also
strftime() and strptime() behavior
and
.
datetime.__format__(format)
Same as
. This makes it possible to specify a format string for a
object in
and when using
. See also
strftime() and strptime() behavior
and
.
Examples of usage: datetime
Examples of working with
objects:
>>> importdatetimeasdt>>> # Using datetime.combine()>>> d=dt.date(2005,7,14)>>> t=dt.time(12,30)>>> dt.datetime.combine(d,t)datetime.datetime(2005, 7, 14, 12, 30)>>> # Using datetime.now()>>> dt.datetime.now()datetime.datetime(2007, 12, 6, 16, 29, 43, 79043) # GMT +1>>> dt.datetime.now(dt.timezone.utc)datetime.datetime(2007, 12, 6, 15, 29, 43, 79060, tzinfo=datetime.timezone.utc)>>> # Using datetime.strptime()>>> my_datetime=dt.datetime.strptime("21/11/06 16:30","%d/%m/%y %H:%M")>>> my_datetimedatetime.datetime(2006, 11, 21, 16, 30)>>> # Using datetime.timetuple() to get tuple of all attributes>>> tt=my_datetime.timetuple()>>> foritintt:... print(it)...2006 # year11 # month21 # day16 # hour30 # minute0 # second1 # weekday (0 = Monday)325 # number of days since 1st January-1 # dst - method tzinfo.dst() returned None>>> # Date in ISO format>>> ic=my_datetime.isocalendar()>>> foritinic:... print(it)...2006 # ISO year47 # ISO week2 # ISO weekday>>> # Formatting a datetime>>> my_datetime.strftime("%A, %d. %B %Y %I:%M%p")'Tuesday, 21. November 2006 04:30PM'>>> 'The {1} is {0:%d}, the {2} is {0:%B}, the {3} is {0:%I:%M%p}.'.format(my_datetime,"day","month","time")'The day is 21, the month is November, the time is 04:30PM.'The example below defines a
subclass capturing time zone information for Kabul, Afghanistan, which used +4 UTC until 1945 and then +4:30 UTC thereafter:
importdatetimeasdtclassKabulTz(dt.tzinfo):# Kabul used +4 until 1945, when they moved to +4:30UTC_MOVE_DATE=dt.datetime(1944,12,31,20,tzinfo=dt.timezone.utc)defutcoffset(self,when):ifwhen.year<1945:returndt.timedelta(hours=4)elif(1945,1,1,0,0)<=when.timetuple()[:5]<(1945,1,1,0,30):# An ambiguous ("imaginary") half-hour range representing# a 'fold' in time due to the shift from +4 to +4:30.# If when falls in the imaginary range, use fold to decide how# to resolve. See PEP 495.returndt.timedelta(hours=4,minutes=(30ifwhen.foldelse0))else:returndt.timedelta(hours=4,minutes=30)deffromutc(self,when):# Follow same validations as in datetime.tzinfoifnotisinstance(when,dt.datetime):raiseTypeError("fromutc() requires a datetime argument")ifwhen.tzinfoisnotself:raiseValueError("when.tzinfo is not self")# A custom implementation is required for fromutc as# the input to this function is a datetime with utc values# but with a tzinfo set to self.# See datetime.astimezone or fromtimestamp.ifwhen.replace(tzinfo=dt.timezone.utc)>=self.UTC_MOVE_DATE:returnwhen+dt.timedelta(hours=4,minutes=30)else:returnwhen+dt.timedelta(hours=4)defdst(self,when):# Kabul does not observe daylight saving time.returndt.timedelta(0)deftzname(self,when):ifwhen>=self.UTC_MOVE_DATE:return"+04:30"return"+04"Usage of KabulTz from above:
>>> tz1=KabulTz()>>> # Datetime before the change>>> dt1=dt.datetime(1900,11,21,16,30,tzinfo=tz1)>>> print(dt1.utcoffset())4:00:00>>> # Datetime after the change>>> dt2=dt.datetime(2006,6,14,13,0,tzinfo=tz1)>>> print(dt2.utcoffset())4:30:00>>> # Convert datetime to another time zone>>> dt3=dt2.astimezone(dt.timezone.utc)>>> dt3datetime.datetime(2006, 6, 14, 8, 30, tzinfo=datetime.timezone.utc)>>> dt2datetime.datetime(2006, 6, 14, 13, 0, tzinfo=KabulTz())>>> dt2==dt3Truetime objects
A
object represents a (local) time of day, independent of any particular day, and subject to adjustment via a
object.
classdatetime.time(hour=0, minute=0, second=0, microsecond=0, tzinfo=None, *, fold=0)
All arguments are optional. tzinfo may be None, or an instance of a
subclass. The remaining arguments must be integers in the following ranges:
0<=hour<24,
0<=minute<60,
0<=second<60,
0<=microsecond<1000000,
foldin[0,1].
If an argument outside those ranges is given,
is raised. All default to 0 except tzinfo, which defaults to None.
Class attributes:
time.min
The earliest representable
, time(0,0,0,0).
time.max
The latest representable
, time(23,59,59,999999).
time.resolution
The smallest possible difference between non-equal
objects, timedelta(microseconds=1), although note that arithmetic on time objects is not supported.
Instance attributes (read-only):
time.hour
In range(24).
time.minute
In range(60).
time.second
In range(60).
time.microsecond
In range(1000000).
time.tzinfo
The object passed as the tzinfo argument to the
constructor, or None if none was passed.
time.fold
In [0,1]. Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The values 0 and 1 represent, respectively, the earlier and later of the two moments with the same wall time representation.
Added in version 3.6.
objects support equality and order comparisons, where a is considered less than b when a precedes b in time.
Naive and aware time objects are never equal. Order comparison between naive and aware time objects raises
.
If both comparands are aware, and have the same
attribute, the tzinfo and fold attributes are ignored and the base times are compared. If both comparands are aware and have different tzinfo attributes, the comparands are first adjusted by subtracting their UTC offsets (obtained from self.utcoffset()).
Changed in version 3.3: Equality comparisons between aware and naive
instances don’t raise
.
In Boolean contexts, a
object is always considered to be true.
Changed in version 3.5: Before Python 3.5, a
object was considered to be false if it represented midnight in UTC. This behavior was considered obscure and error-prone and has been removed in Python 3.5. See
for more information.
Other constructors:
classmethodtime.fromisoformat(time_string)
Return a
corresponding to a time_string in any valid ISO 8601 format, with the following exceptions:
Time zone offsets may have fractional seconds.
The leading T, normally required in cases where there may be ambiguity between a date and a time, is not required.
Fractional seconds may have any number of digits (anything beyond 6 will be truncated).
Fractional hours and minutes are not supported.
Examples:
>>> importdatetimeasdt>>> dt.time.fromisoformat('04:23:01')datetime.time(4, 23, 1)>>> dt.time.fromisoformat('T04:23:01')datetime.time(4, 23, 1)>>> dt.time.fromisoformat('T042301')datetime.time(4, 23, 1)>>> dt.time.fromisoformat('04:23:01.000384')datetime.time(4, 23, 1, 384)>>> dt.time.fromisoformat('04:23:01,000384')datetime.time(4, 23, 1, 384)>>> dt.time.fromisoformat('04:23:01+04:00')datetime.time(4, 23, 1, tzinfo=datetime.timezone(datetime.timedelta(seconds=14400)))>>> dt.time.fromisoformat('04:23:01Z')datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc)>>> dt.time.fromisoformat('04:23:01+00:00')datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc)Added in version 3.7.
Changed in version 3.11: Previously, this method only supported formats that could be emitted by
.
classmethodtime.strptime(date_string, format)
Return a
corresponding to date_string, parsed according to format.
If format does not contain microseconds or timezone information, this is equivalent to:
time(*(time.strptime(date_string,format)[3:6]))
is raised if the date_string and format cannot be parsed by time.strptime() or if it returns a value which is not a time tuple. See also
strftime() and strptime() behavior
and
.
Added in version 3.14.
Instance methods:
time.replace(hour=self.hour, minute=self.minute, second=self.second, microsecond=self.microsecond, tzinfo=self.tzinfo, *, fold=0)
Return a new
with the same values, but with specified parameters updated. Note that tzinfo=None can be specified to create a naive time from an aware time, without conversion of the time data.
objects are also supported by generic function
.
Changed in version 3.6: Added the fold parameter.
time.isoformat(timespec='auto')
Return a string representing the time in ISO 8601 format, one of:
HH:MM:SS.ffffff, if
is not 0
HH:MM:SS, if
is 0
HH:MM:SS.ffffff+HH:MM[:SS[.ffffff]], if
does not return None
HH:MM:SS+HH:MM[:SS[.ffffff]], if
is 0 and
does not return None
The optional argument timespec specifies the number of additional components of the time to include (the default is 'auto'). It can be one of the following:
'auto': Same as 'seconds' if
is 0, same as 'microseconds' otherwise.
'hours': Include the
in the two-digit HH format.
'minutes': Include
and
in HH:MM format.
'seconds': Include
,
, and
in HH:MM:SS format.
'milliseconds': Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.
'microseconds': Include full time in HH:MM:SS.ffffff format.
Note
Excluded time components are truncated, not rounded.
will be raised on an invalid timespec argument.
Example:
>>> importdatetimeasdt>>> dt.time(hour=12,minute=34,second=56,microsecond=123456).isoformat(timespec='minutes')'12:34'>>> my_time=dt.time(hour=12,minute=34,second=56,microsecond=0)>>> my_time.isoformat(timespec='microseconds')'12:34:56.000000'>>> my_time.isoformat(timespec='auto')'12:34:56'Changed in version 3.6: Added the timespec parameter.
time.__str__()
For a time t, str(t) is equivalent to t.isoformat().
time.strftime(format)
Return a string representing the time, controlled by an explicit format string. See also
strftime() and strptime() behavior
and
.
time.__format__(format)
Same as
. This makes it possible to specify a format string for a
object in
and when using
. See also
strftime() and strptime() behavior
and
.
time.utcoffset()
If
is None, returns None, else returns self.tzinfo.utcoffset(None), and raises an exception if the latter doesn’t return None or a
object with magnitude less than one day.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
time.dst()
If
is None, returns None, else returns self.tzinfo.dst(None), and raises an exception if the latter doesn’t return None, or a
object with magnitude less than one day.
Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.
time.tzname()
If
is None, returns None, else returns self.tzinfo.tzname(None), or raises an exception if the latter doesn’t return None or a string object.
Examples of usage: time
Examples of working with a
object:
>>> importdatetimeasdt>>> classTZ1(dt.tzinfo):... defutcoffset(self,when):... returndt.timedelta(hours=1)... defdst(self,when):... returndt.timedelta(0)... deftzname(self,when):... return"+01:00"... def__repr__(self):... returnf"{self.__class__.__name__}()"...>>> t=dt.time(12,10,30,tzinfo=TZ1())>>> tdatetime.time(12, 10, 30, tzinfo=TZ1())>>> t.isoformat()'12:10:30+01:00'>>> t.dst()datetime.timedelta(0)>>> t.tzname()'+01:00'>>> t.strftime("%H:%M:%S %Z")'12:10:30 +01:00'>>> 'The {} is {:%H:%M}.'.format("time",t)'The time is 12:10.'tzinfo objects
classdatetime.tzinfo
This is an
, meaning that this class should not be instantiated directly. Define a subclass of tzinfo to capture information about a particular time zone.
An instance of (a concrete subclass of) tzinfo can be passed to the constructors for
and
objects. The latter objects view their attributes as being in local time, and the tzinfo object supports methods revealing offset of local time from UTC, the name of the time zone, and DST offset, all relative to a date or time object passed to them.
You need to derive a concrete subclass, and (at least) supply implementations of the standard tzinfo methods needed by the
methods you use. The datetime module provides
, a simple concrete subclass of tzinfo which can represent time zones with fixed offset from UTC such as UTC itself or North American EST and EDT.
Special requirement for pickling: A tzinfo subclass must have an
method that can be called with no arguments, otherwise it can be pickled but possibly not unpickled again. This is a technical requirement that may be relaxed in the future.
A concrete subclass of tzinfo may need to implement the following methods. Exactly which methods are needed depends on the uses made of aware datetime objects. If in doubt, simply implement all of them.
tzinfo.utcoffset(dt)
Return offset of local time from UTC, as a
object that is positive east of UTC. If local time is west of UTC, this should be negative.
This represents the total offset from UTC; for example, if a
object represents both time zone and DST adjustments, utcoffset() should return their sum. If the UTC offset isn’t known, return None. Else the value returned must be a
object strictly between -timedelta(hours=24) and timedelta(hours=24) (the magnitude of the offset must be less than one day). Most implementations of utcoffset() will probably look like one of these two:
returnCONSTANT# fixed-offset classreturnCONSTANT+self.dst(dt)# daylight-aware classIf utcoffset() does not return None,
should not return None either.
The default implementation of utcoffset() raises
.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
tzinfo.dst(dt)
Return the daylight saving time (DST) adjustment, as a
object or None if DST information isn’t known.
Return timedelta(0) if DST is not in effect. If DST is in effect, return the offset as a
object (see
for details). Note that DST offset, if applicable, has already been added to the UTC offset returned by utcoffset(), so there’s no need to consult dst() unless you’re interested in obtaining DST info separately. For example,
calls its
attribute’s dst() method to determine how the
flag should be set, and
calls dst() to account for DST changes when crossing time zones.
An instance tz of a
subclass that models both standard and daylight times must be consistent in this sense:
tz.utcoffset(dt)-tz.dst(dt)
must return the same result for every
dt with dt.tzinfo==tz. For sane tzinfo subclasses, this expression yields the time zone’s “standard offset”, which should not depend on the date or the time, but only on geographic location. The implementation of
relies on this, but cannot detect violations; it’s the programmer’s responsibility to ensure it. If a tzinfo subclass cannot guarantee this, it may be able to override the default implementation of
to work correctly with astimezone() regardless.
Most implementations of dst() will probably look like one of these two:
importdatetimeasdtdefdst(self,when):# a fixed-offset class: doesn't account for DSTreturndt.timedelta(0)or:
importdatetimeasdtdefdst(self,when):# Code to set dston and dstoff to the time zone's DST# transition times based on the input when.year, and expressed# in standard local time.ifdston<=when.replace(tzinfo=None)<dstoff:returndt.timedelta(hours=1)else:returndt.timedelta(0)The default implementation of dst() raises
.
Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.
tzinfo.tzname(dt)
Return the time zone name corresponding to the
object dt, as a string. Nothing about string names is defined by the datetime module, and there’s no requirement that it mean anything in particular. For example, "GMT", "UTC", "-500", "-5:00", "EDT", "US/Eastern", "America/NewYork" are all valid replies. Return None if a string name isn’t known. Note that this is a method rather than a fixed string primarily because some
subclasses will wish to return different names depending on the specific value of dt passed, especially if the tzinfo class is accounting for daylight time.
The default implementation of tzname() raises
.
These methods are called by a
or
object, in response to their methods of the same names. A datetime object passes itself as the argument, and a time object passes None as the argument. A
subclass’s methods should therefore be prepared to accept a dt argument of None, or of class datetime.
When None is passed, it’s up to the class designer to decide the best response. For example, returning None is appropriate if the class wishes to say that time objects don’t participate in the
protocols. It may be more useful for utcoffset(None) to return the standard UTC offset, as there is no other convention for discovering the standard offset.
When a
object is passed in response to a datetime method, dt.tzinfo is the same object as self.
methods can rely on this, unless user code calls tzinfo methods directly. The intent is that the tzinfo methods interpret dt as being in local time, and not need worry about objects in other time zones.
There is one more
method that a subclass may wish to override:
tzinfo.fromutc(dt)
This is called from the default
implementation. When called from that, dt.tzinfo is self, and dt’s date and time data are to be viewed as expressing a UTC time. The purpose of fromutc() is to adjust the date and time data, returning an equivalent datetime in self’s local time.
Most
subclasses should be able to inherit the default fromutc() implementation without problems. It’s strong enough to handle fixed-offset time zones, and time zones accounting for both standard and daylight time, and the latter even if the DST transition times differ in different years. An example of a time zone the default fromutc() implementation may not handle correctly in all cases is one where the standard offset (from UTC) depends on the specific date and time passed, which can happen for political reasons. The default implementations of
and fromutc() may not produce the result you want if the result is one of the hours straddling the moment the standard offset changes.
Skipping code for error cases, the default fromutc() implementation acts like:
importdatetimeasdtdeffromutc(self,when):# raise ValueError error if when.tzinfo is not selfdtoff=when.utcoffset()dtdst=when.dst()# raise ValueError if dtoff is None or dtdst is Nonedelta=dtoff-dtdst# this is self's standard offsetifdelta:when+=delta# convert to standard local timedtdst=when.dst()# raise ValueError if dtdst is Noneifdtdst:returnwhen+dtdstelse:returnwhenIn the following
file there are some examples of
classes:
importdatetimeasdt# A class capturing the platform's idea of local time.# (May result in wrong values on historical times in# timezones where UTC offset and/or the DST rules had# changed in the past.)importtimeZERO=dt.timedelta(0)HOUR=dt.timedelta(hours=1)SECOND=dt.timedelta(seconds=1)STDOFFSET=dt.timedelta(seconds=-time.timezone)iftime.daylight:DSTOFFSET=dt.timedelta(seconds=-time.altzone)else:DSTOFFSET=STDOFFSETDSTDIFF=DSTOFFSET-STDOFFSETclassLocalTimezone(dt.tzinfo):deffromutc(self,when):assertwhen.tzinfoisselfstamp=(when-dt.datetime(1970,1,1,tzinfo=self))//SECONDargs=time.localtime(stamp)[:6]dst_diff=DSTDIFF//SECOND# Detect foldfold=(args==time.localtime(stamp-dst_diff))returndt.datetime(*args,microsecond=when.microsecond,tzinfo=self,fold=fold)defutcoffset(self,when):ifself._isdst(when):returnDSTOFFSETelse:returnSTDOFFSETdefdst(self,when):ifself._isdst(when):returnDSTDIFFelse:returnZEROdeftzname(self,when):returntime.tzname[self._isdst(when)]def_isdst(self,when):tt=(when.year,when.month,when.day,when.hour,when.minute,when.second,when.weekday(),0,0)stamp=time.mktime(tt)tt=time.localtime(stamp)returntt.tm_isdst>0Local=LocalTimezone()# A complete implementation of current DST rules for major US time zones.deffirst_sunday_on_or_after(when):days_to_go=6-when.weekday()ifdays_to_go:when+=dt.timedelta(days_to_go)returnwhen# US DST Rules## This is a simplified (i.e., wrong for a few cases) set of rules for US# DST start and end times. For a complete and up-to-date set of DST rules# and timezone definitions, visit the Olson Database (or try pytz):# http://www.twinsun.com/tz/tz-link.htm# https://sourceforge.net/projects/pytz/ (might not be up-to-date)## In the US, since 2007, DST starts at 2am (standard time) on the second# Sunday in March, which is the first Sunday on or after Mar 8.DSTSTART_2007=dt.datetime(1,3,8,2)# and ends at 2am (DST time) on the first Sunday of Nov.DSTEND_2007=dt.datetime(1,11,1,2)# From 1987 to 2006, DST used to start at 2am (standard time) on the first# Sunday in April and to end at 2am (DST time) on the last# Sunday of October, which is the first Sunday on or after Oct 25.DSTSTART_1987_2006=dt.datetime(1,4,1,2)DSTEND_1987_2006=dt.datetime(1,10,25,2)# From 1967 to 1986, DST used to start at 2am (standard time) on the last# Sunday in April (the one on or after April 24) and to end at 2am (DST time)# on the last Sunday of October, which is the first Sunday# on or after Oct 25.DSTSTART_1967_1986=dt.datetime(1,4,24,2)DSTEND_1967_1986=DSTEND_1987_2006defus_dst_range(year):# Find start and end times for US DST. For years before 1967, return# start = end for no DST.if2006<year:dststart,dstend=DSTSTART_2007,DSTEND_2007elif1986<year<2007:dststart,dstend=DSTSTART_1987_2006,DSTEND_1987_2006elif1966<year<1987:dststart,dstend=DSTSTART_1967_1986,DSTEND_1967_1986else:return(dt.datetime(year,1,1),)*2start=first_sunday_on_or_after(dststart.replace(year=year))end=first_sunday_on_or_after(dstend.replace(year=year))returnstart,endclassUSTimeZone(dt.tzinfo):def__init__(self,hours,reprname,stdname,dstname):self.stdoffset=dt.timedelta(hours=hours)self.reprname=reprnameself.stdname=stdnameself.dstname=dstnamedef__repr__(self):returnself.reprnamedeftzname(self,when):ifself.dst(when):returnself.dstnameelse:returnself.stdnamedefutcoffset(self,when):returnself.stdoffset+self.dst(when)defdst(self,when):ifwhenisNoneorwhen.tzinfoisNone:# An exception may be sensible here, in one or both cases.# It depends on how you want to treat them. The default# fromutc() implementation (called by the default astimezone()# implementation) passes a datetime with when.tzinfo is self.returnZEROassertwhen.tzinfoisselfstart,end=us_dst_range(when.year)# Can't compare naive to aware objects, so strip the timezone from# when first.when=when.replace(tzinfo=None)ifstart+HOUR<=when<end-HOUR:# DST is in effect.returnHOURifend-HOUR<=when<end:# Fold (an ambiguous hour): use when.fold to disambiguate.returnZEROifwhen.foldelseHOURifstart<=when<start+HOUR:# Gap (a non-existent hour): reverse the fold rule.returnHOURifwhen.foldelseZERO# DST is off.returnZEROdeffromutc(self,when):assertwhen.tzinfoisselfstart,end=us_dst_range(when.year)start=start.replace(tzinfo=self)end=end.replace(tzinfo=self)std_time=when+self.stdoffsetdst_time=std_time+HOURifend<=dst_time<end+HOUR:# Repeated hourreturnstd_time.replace(fold=1)ifstd_time<startordst_time>=end:# Standard timereturnstd_timeifstart<=std_time<end-HOUR:# Daylight saving timereturndst_timeEastern=USTimeZone(-5,"Eastern","EST","EDT")Central=USTimeZone(-6,"Central","CST","CDT")Mountain=USTimeZone(-7,"Mountain","MST","MDT")Pacific=USTimeZone(-8,"Pacific","PST","PDT")Note that there are unavoidable subtleties twice per year in a
subclass accounting for both standard and daylight time, at the DST transition points. For concreteness, consider US Eastern (UTC -0500), where EDT begins the minute after 1:59 (EST) on the second Sunday in March, and ends the minute after 1:59 (EDT) on the first Sunday in November:
UTC3:MM4:MM5:MM6:MM7:MM8:MMEST22:MM23:MM0:MM1:MM2:MM3:MMEDT23:MM0:MM1:MM2:MM3:MM4:MMstart22:MM23:MM0:MM1:MM3:MM4:MMend23:MM0:MM1:MM1:MM2:MM3:MMWhen DST starts (the “start” line), the local wall clock leaps from 1:59 to 3:00. A wall time of the form 2:MM doesn’t really make sense on that day, so astimezone(Eastern) won’t deliver a result with hour==2 on the day DST begins. For example, at the Spring forward transition of 2016, we get:
>>> importdatetimeasdt>>> fromtzinfo_examplesimportHOUR,Eastern>>> u0=dt.datetime(2016,3,13,5,tzinfo=dt.timezone.utc)>>> foriinrange(4):... u=u0+i*HOUR... t=u.astimezone(Eastern)... print(u.time(),'UTC =',t.time(),t.tzname())...05:00:00 UTC = 00:00:00 EST06:00:00 UTC = 01:00:00 EST07:00:00 UTC = 03:00:00 EDT08:00:00 UTC = 04:00:00 EDTWhen DST ends (the “end” line), there’s a potentially worse problem: there’s an hour that can’t be spelled unambiguously in local wall time: the last hour of daylight time. In Eastern, that’s times of the form 5:MM UTC on the day daylight time ends. The local wall clock leaps from 1:59 (daylight time) back to 1:00 (standard time) again. Local times of the form 1:MM are ambiguous.
mimics the local clock’s behavior by mapping two adjacent UTC hours into the same local hour then. In the Eastern example, UTC times of the form 5:MM and 6:MM both map to 1:MM when converted to Eastern, but earlier times have the
attribute set to 0 and the later times have it set to 1. For example, at the Fall back transition of 2016, we get:
>>> importdatetimeasdt>>> fromtzinfo_examplesimportHOUR,Eastern>>> u0=dt.datetime(2016,11,6,4,tzinfo=dt.timezone.utc)>>> foriinrange(4):... u=u0+i*HOUR... t=u.astimezone(Eastern)... print(u.time(),'UTC =',t.time(),t.tzname(),t.fold)...04:00:00 UTC = 00:00:00 EDT 005:00:00 UTC = 01:00:00 EDT 006:00:00 UTC = 01:00:00 EST 107:00:00 UTC = 02:00:00 EST 0Note that the
instances that differ only by the value of the
attribute are considered equal in comparisons.
Applications that can’t bear wall-time ambiguities should explicitly check the value of the
attribute or avoid using hybrid
subclasses; there are no ambiguities when using
, or any other fixed-offset tzinfo subclass (such as a class representing only EST (fixed offset -5 hours), or only EDT (fixed offset -4 hours)).
See also
The datetime module has a basic
class (for handling arbitrary fixed offsets from UTC) and its
attribute (a UTC timezone instance).
zoneinfo brings the IANA time zone database (also known as the Olson database) to Python, and its usage is recommended.
The Time Zone Database (often called tz, tzdata or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules.
timezone objects
The
class is a subclass of
, each instance of which represents a time zone defined by a fixed offset from UTC.
Objects of this class cannot be used to represent time zone information in the locations where different offsets are used in different days of the year or where historical changes have been made to civil time.
classdatetime.timezone(offset, name=None)
The offset argument must be specified as a
object representing the difference between the local time and UTC. It must be strictly between -timedelta(hours=24) and timedelta(hours=24), otherwise
is raised.
The name argument is optional. If specified it must be a string that will be used as the value returned by the
method.
Added in version 3.2.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
timezone.utcoffset(dt)
Return the fixed value specified when the
instance is constructed.
The dt argument is ignored. The return value is a
instance equal to the difference between the local time and UTC.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
timezone.tzname(dt)
Return the fixed value specified when the
instance is constructed.
If name is not provided in the constructor, the name returned by tzname(dt) is generated from the value of the offset as follows. If offset is timedelta(0), the name is “UTC”, otherwise it is a string in the format UTC±HH:MM, where ± is the sign of offset, HH and MM are two digits of offset.hours and offset.minutes respectively.
Changed in version 3.6: Name generated from offset=timedelta(0) is now plain 'UTC', not 'UTC+00:00'.
timezone.dst(dt)
Always returns None.
timezone.fromutc(dt)
Return dt+offset. The dt argument must be an aware
instance, with tzinfo set to self.
Class attributes:
timezone.utc
The UTC time zone, timezone(timedelta(0)).
strftime() and strptime() behavior
,
, and
objects all support a strftime(format) method, to create a string representing the time under the control of an explicit format string.
Conversely, the
,
and
class methods create an object from a string representing the time and a corresponding format string.
The table below provides a high-level comparison of
versus
:
strftime
strptime
Usage
Convert object to a string according to a given format
Parse a string into an object given a corresponding format
Type of method
Instance method
Class method
Signature
strftime(format)
strptime(date_string,format)
strftime() and strptime() format codes
These methods accept format codes that can be used to parse and format dates:
>>> importdatetimeasdt>>> dt.datetime.strptime('31/01/22 23:59:59.999999',... '%d/%m/%y %H:%M:%S.%f')datetime.datetime(2022, 1, 31, 23, 59, 59, 999999)>>> _.strftime('%a%d %b %Y, %I:%M%p')'Mon 31 Jan 2022, 11:59PM'The following is a list of all the format codes that the 1989 C standard requires, and these work on all platforms with a standard C implementation.
Directive
Meaning
Example
Notes
%a
Weekday as locale’s abbreviated name.
Sun, Mon, …, Sat (en_US);
So, Mo, …, Sa (de_DE)
(1)
%A
Weekday as locale’s full name.
Sunday, Monday, …, Saturday (en_US);
Sonntag, Montag, …, Samstag (de_DE)
(1)
%w
Weekday as a decimal number, where 0 is Sunday and 6 is Saturday.
0, 1, …, 6
%d
Day of the month as a zero-padded decimal number.
01, 02, …, 31
(9)
%b
Month as locale’s abbreviated name.
Jan, Feb, …, Dec (en_US);
Jan, Feb, …, Dez (de_DE)
(1)
%B
Month as locale’s full name.
January, February, …, December (en_US);
Januar, Februar, …, Dezember (de_DE)
(1)
%m
Month as a zero-padded decimal number.
01, 02, …, 12
(9)
%y
Year without century as a zero-padded decimal number.
00, 01, …, 99
(9)
%Y
Year with century as a decimal number.
0001, 0002, …, 2013, 2014, …, 9998, 9999
(2)
%H
Hour (24-hour clock) as a zero-padded decimal number.
00, 01, …, 23
(9)
%I
Hour (12-hour clock) as a zero-padded decimal number.
01, 02, …, 12
(9)
%p
Locale’s equivalent of either AM or PM.
AM, PM (en_US);
am, pm (de_DE)
(1), (3)
%M
Minute as a zero-padded decimal number.
00, 01, …, 59
(9)
%S
Second as a zero-padded decimal number.
00, 01, …, 59
(4), (9)
%f
Microsecond as a decimal number, zero-padded to 6 digits.
000000, 000001, …, 999999
(5)
%z
UTC offset in the form ±HHMM[SS[.ffffff]] (empty string if the object is naive).
(empty), +0000, -0400, +1030, +063415, -030712.345216
(6)
%Z
Time zone name (empty string if the object is naive).
(empty), UTC, GMT
(6)
%j
Day of the year as a zero-padded decimal number.
001, 002, …, 366
(9)
%U
Week number of the year (Sunday as the first day of the week) as a zero-padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.
00, 01, …, 53
(7), (9)
%W
Week number of the year (Monday as the first day of the week) as a zero-padded decimal number. All days in a new year preceding the first Monday are considered to be in week 0.
00, 01, …, 53
(7), (9)
%c
Locale’s appropriate date and time representation.
Tue Aug 16 21:30:00 1988 (en_US);
Di 16 Aug 21:30:00 1988 (de_DE)
(1)
%x
Locale’s appropriate date representation.
08/16/88 (None);
08/16/1988 (en_US);
16.08.1988 (de_DE)
(1)
%X
Locale’s appropriate time representation.
21:30:00 (en_US);
21:30:00 (de_DE)
(1)
%%
A literal '%' character.
%
Several additional directives not required by the C89 standard are included for convenience. These parameters all correspond to ISO 8601 date values.
Directive
Meaning
Example
Notes
%G
ISO 8601 year with century representing the year that contains the greater part of the ISO week (%V).
0001, 0002, …, 2013, 2014, …, 9998, 9999
(8)
%u
ISO 8601 weekday as a decimal number where 1 is Monday.
1, 2, …, 7
%V
ISO 8601 week as a decimal number with Monday as the first day of the week. Week 01 is the week containing Jan 4.
01, 02, …, 53
(8), (9)
%:z
UTC offset in the form ±HH:MM[:SS[.ffffff]] (empty string if the object is naive).
(empty), +00:00, -04:00, +10:30, +06:34:15, -03:07:12.345216
(6)
These may not be available on all platforms when used with the
method. The ISO 8601 year and ISO 8601 week directives are not interchangeable with the year and week number directives above. Calling
with incomplete or ambiguous ISO 8601 directives will raise a
.
The full set of format codes supported varies across platforms, because Python calls the platform C library’s strftime() function, and platform variations are common. To see the full set of format codes supported on your platform, consult the
documentation. There are also differences between platforms in handling of unsupported format specifiers.
Added in version 3.6: %G, %u and %V were added.
Added in version 3.12: %:z was added.
Technical detail
Broadly speaking, d.strftime(fmt) acts like the
module’s time.strftime(fmt,d.timetuple()) although not all objects support a
method.
For the
and
class methods, the default value is 1900-01-01T00:00:00.000: any components not specified in the format string will be pulled from the default value.
Note
Format strings without separators can be ambiguous for parsing. For example, with %Y%m%d, the string 2026111 may be parsed either as 2026-11-01 or as 2026-01-11. Use separators to ensure the input is parsed as intended.
Note
When used to parse partial dates lacking a year,
and
will raise when encountering February 29 because the default year of 1900 is not a leap year. Always add a default leap year to partial date strings before parsing.
>>> importdatetimeasdt>>> value="2/29">>> dt.datetime.strptime(value,"%m/%d")Traceback (most recent call last):...ValueError: day 29 must be in range 1..28 for month 2 in year 1900>>> dt.datetime.strptime(f"1904 {value}","%Y %m/%d")datetime.datetime(1904, 2, 29, 0, 0)Using datetime.strptime(date_string,format) is equivalent to:
datetime(*(time.strptime(date_string,format)[0:6]))except when the format includes sub-second components or time zone offset information, which are supported in datetime.strptime but are discarded by time.strptime.
For
objects, the format codes for year, month, and day should not be used, as time objects have no such values. If they’re used anyway, 1900 is substituted for the year, and 1 for the month and day.
For
objects, the format codes for hours, minutes, seconds, and microseconds should not be used, as date objects have no such values. If they’re used anyway, 0 is substituted for them.
For the same reason, handling of format strings containing Unicode code points that can’t be represented in the charset of the current locale is also platform-dependent. On some platforms such code points are preserved intact in the output, while on others strftime may raise
or return an empty string instead.
Notes:
Because the format depends on the current locale, care should be taken when making assumptions about the output value. Field orderings will vary (for example, “month/day/year” versus “day/month/year”), and the output may contain non-ASCII characters.
The
method can parse years in the full [1, 9999] range, but years < 1000 must be zero-filled to 4-digit width.
Changed in version 3.2: In previous versions,
method was restricted to years >= 1900.
Changed in version 3.3: In version 3.2,
method was restricted to years >= 1000.
When used with the
method, the %p directive only affects the output hour field if the %I directive is used to parse the hour.
Unlike the
module, the datetime module does not support leap seconds.
When used with the
method, the %f directive accepts from one to six digits and zero pads on the right. %f is an extension to the set of format characters in the C standard (but implemented separately in datetime objects, and therefore always available).
For a naive object, the %z, %:z and %Z format codes are replaced by empty strings.
For an aware object:
%z
is transformed into a string of the form ±HHMM[SS[.ffffff]], where HH is a 2-digit string giving the number of UTC offset hours, MM is a 2-digit string giving the number of UTC offset minutes, SS is a 2-digit string giving the number of UTC offset seconds and ffffff is a 6-digit string giving the number of UTC offset microseconds. The ffffff part is omitted when the offset is a whole number of seconds and both the ffffff and the SS part is omitted when the offset is a whole number of minutes. For example, if utcoffset() returns timedelta(hours=-3,minutes=-30), %z is replaced with the string '-0330'.
Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.
Changed in version 3.7: When the %z directive is provided to the
method, the UTC offsets can have a colon as a separator between hours, minutes and seconds. For example, '+01:00:00' will be parsed as an offset of one hour. In addition, providing 'Z' is identical to '+00:00'.
%:zBehaves exactly as %z, but has a colon separator added between hours, minutes and seconds.
%ZIn
, %Z is replaced by an empty string if
returns None; otherwise %Z is replaced by the returned value, which must be a string.
only accepts certain values for %Z:
any value in time.tzname for your machine’s locale
the hard-coded values UTC and GMT
So someone living in Japan may have JST, UTC, and GMT as valid values, but probably not EST. It will raise ValueError for invalid values.
Changed in version 3.2: When the %z directive is provided to the
method, an aware
object will be produced. The tzinfo of the result will be set to a
instance.
When used with the
method, %U and %W are only used in calculations when the day of the week and the calendar year (%Y) are specified.
Similar to %U and %W, %V is only used in calculations when the day of the week and the ISO year (%G) are specified in a
format string. Also note that %G and %Y are not interchangeable.
When used with the
method, the leading zero is optional for formats %d, %m, %H, %I, %M, %S, %j, %U, %W, and %V. Format %y does require a leading zero.
When parsing a month and day using
, always include a year in the format. If the value you need to parse lacks a year, append an explicit dummy leap year. Otherwise your code will raise an exception when it encounters leap day because the default year used by the parser (1900) is not a leap year. Users run into that bug every leap year.
>>> month_day="02/29">>> dt.datetime.strptime(f"{month_day};1984","%m/%d;%Y")# No leap year bug.datetime.datetime(1984, 2, 29, 0, 0)Deprecated since version 3.13, will be removed in version 3.15:
calls using a format string containing a day of month without a year now emit a
. In 3.15 or later we may change this into an error or change the default year to a leap year. See
.
Footnotes