Did you feel it? Did you get just a little bit more done today? A few minutes ago, at 6:59:60 pm local time, an extra second was added to the calendar. That’s right, after second #59, there was #60, then #00. It was done then because it was midnight in Universal Coordinated Time, UTC. It’s called a Leap Second.
So why add a second? Who’s going to even notice? Probably not you or I, but people in science doing precise measurement, especially of celestial objects, needed it. Do you need to reset your clock? Not unless you’re really obsessed with accuracy.
The change compensates for the gradual slowing of the Earth as it orbits around the Sun. Or as it spins on it’s axis. Or both. I guess it’s slowly sliding down the gravity well into the Sun, but not at any rate we’ll ever need to worry about.
You computer may have already reset it’s clock, especially if you have it set up to set it’s internal clock over the internet. Things like cell phones will also be adjusted by the network. Your GPS doesn’t care. Apparently, the GPS satellites use their own time scheme to keep time and it’s already a dozen or so seconds off UTC. The time you see on the screen is adjusted by a “UTC Offset,” a fudge-factor to make it’s time look right to you.
So if you thought 2008 would never end, maybe it was because it was a leap year and was 24 hours and one second longer…