From cppreference.com
classleap_second;(since C++20)The class leap_second represents the date and time of a leap second insertion.
Users cannot construct leap_second objects except by copying from existing leap_second objects. The library implementation creates leap_second objects when it initializes the time zone database and provides const access to these objects.
leap_second has a defaulted copy constructor and a defaulted copy assignment operator.
Member functions
obtains the time of leap second insertion
(public member function)
Nonmember functions
Helper classes