“23:59:60”，将不再出现

“23:59:60”这一特殊时间戳，今后将不再出现。

A decision by the international metrology community will effectively end the practice of adding leap seconds to Coordinated Universal Time (UTC) from May 20, 2027, phasing out a mechanism that has been in use for more than half a century.

The 28th General Conference on Weights and Measures (CGPM) was held in Versailles, France, from Oct 13 to 15 and adopted the resolution, according to China's State Administration for Market Regulation. The resolution raises the maximum permitted difference between UTC and Universal Time (UT1), which is based on Earth's rotation, to 3,600 seconds, or one hour.

什么是闰秒？

Leap seconds were first introduced in 1972 to compensate for variations in the Earth's speed. Atomic clocks are among the most accurate timekeeping devices in the world. They measure time using electromagnetic radiation emitted or absorbed by atoms as they change energy levels. One time standard based on atomic clocks is International Atomic Time (TAI).

The timekeeping system based on the Earth's rotation is called Universal Time (UT). Because the Earth's rotation is not constant, the difference between Earth-rotation time (UT1) and Coordinated Universal Time (UTC) can gradually increase. Leap seconds may be added to UTC to keep the difference within a specified range and to keep the two in synch. UTC is the internationally used time standard and the world's benchmark time standard.

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