The Guardian
How an accelerating Earth led experts to adopt the leap hour
Coordinated universal time is kept by atomic clocks, which are steadier than the Earth's rotation. Officials have added 27 leap seconds since 1972 to keep the two in sync, but a minute with 61 seconds can confuse computers. Delegates from 69 countries voted to replace leap seconds with a leap hour, allowing up to an hour of drift, which is not expected to be needed for thousands of years.


