If you end up feel like you had to wait a little too long for Wednesday this week, then holy cow are you sensitive, because, yes, this is in fact the longest Tuesday we’ve experienced since 1992.
It’s one leap second longer than normal to adjust for irregularities in the earth’s rotation. Let’s not mince words: We’re slowing down! We’re adding an average of more than a millisecond to the true solar day every century. Something must be done. And we’re doing it. We’re throwing in an extra second. Right at the end. She goes by the name of 23:59:60 UTC.
Time was (get it?), a second was defined as 1/86,400 of the mean solar day. But that wasn’t good enough for some people. So after diddling around a little bit between the definitions based off the tropical year and the sidereal year, we settled on counting nine-billion-some-odd periods of radiation off the caesium-133 atom.
TL;DR You have an extra second today. Make it count!
