The leap second has been (will be) depreciated and discontinued.
quote:
Time is up for the leap second. Last week, an international coalition of scientists and government agencies voted to retire the dated timekeeping system, which will officially end in 2035.
The decision was made Nov. 18 during a general conference in France held by the International Bureau of Weights and Measures (BIPM), the organization responsible for global timekeeping.
Similar to leap years, leap seconds are a measure of time that get added periodically to clocks to make up for the difference between astronomical time (Universal Time 1, or UT1), also known as the Earth’s rotation, and Coordinated Universal Time (UTC), which is based on the atomic clock.