Chinese scientists have engineered a clock so accurate it could lead to a redefinition of the second and an ultraprecise global time standard. The new optical clock is so accurate that it loses or ...

Timekeepers add a leap second occasionally to keep our clocks and the Earth’s rotation in tune. That could now change.

You’re probably used to the month of February having an extra day every four years, during the leap year. Timekeepers added ...