Earth’s rotation is no longer matching the tidy 24-hour day that our technology assumes. Since 2020, each day has been ...

Thanks to Einstein’s relativity, time flows differently on Mars than on Earth. NIST scientists have now nailed down the difference, showing that Mars clocks tick slightly faster—and fluctuate over the ...

Time moves differently in space. Near black holes, gravity slows clocks and stretches seconds. This explainer reveals how time bends and affects astronauts and Earth.