To keep atomic clocks and those based on the earth’s rotation in sync, GCWM periodically adds a second to UTC; the prospect of having to subtract one, potentially causing major disruption, is prompting it to rethink leap seconds entirely.

Risk of an unprecedented negative adjustment prompts plan to let UTC drift by as much as an hour

To keep atomic clocks and those based on the earth’s rotation in sync, GCWM periodically adds a second to UTC; the prospect of having to subtract one, potentially causing major…