Leap seconds face judgment day as time lords prepare to vote

It's about time: the General Conference on Weights and Measures looks set to end leap seconds in an effort to reach horological harmony. Since 1972, 27 leap seconds have been added to Coordinated Universal Time (UTC) to keep it in step with the astronomical time scale UT1, which is based on Earth's fluctuating rotation. The proposal would increase the permitted difference between UTC and UT1 from 0.9 seconds to one hour, avoiding leap-second adjustments for centuries. Earth's rotation has also s