If you’re reading this before 5:59 p.m. on Tuesday, your clock is wrong.
But it’s not just your clock — it’s pretty much every clock on earth. Fortunately, there is a solution: astronomers will add a single “leap second” at 5:59:59 p.m. MDT Tuesday to sync the world’s clocks with the planet’s rotation once again.
Even though Tuesday will be ever so slightly longer than normal, Patrick Wiggins, a local resident and a Solar System Ambassador for NASA, said most people won’t notice the difference. The leap second should pass without causing any undue distress, though in the past such events have caused some time-sensitive features on a few websites to crash, he said.
Scientists adjust the world’s clocks with leap seconds every once in a while to keep clocks aligned with the Earth’s actual position in space, Wiggins said. The most recent — the one that crashed websites — occurred in 2012. The first few leap seconds were added in 1972, he said, when astronomers first detected a slight discrepancy between the Earth’s rotation and the actual time.