std::chrono::leap_second::date

constexpr std::chrono::sys_seconds date() const noexcept;

Obtains the date and time of the leap second insertion.

A std::chrono::sys_seconds representing the date and time at which the leap second was inserted.

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/chrono/leap_second/date