As John Oliver explained this past Sunday, today is a Leap Second Day. Leap Seconds are things that most people have never heard of, and few people ever think about. But it is another example of the miggling flaws in in the way we track time. Essentially, because of inconsistencies between the Earth's rotation and Coordinated Universal Time, which itself is derived from Universal Atomic Time, which is not the name of a 1970's concept album but certainly could be, we have to make these little adjustments every so often so that May stays in Spring time and children don't have yet another aspect to telling time that they blatantly don't learn in school (seriously, show anyone under 16 an analogue clock and then gird yourself for some truly depressing and painful shit).
Adding or subtracting a Leap Second (yes, like the points on your driver's license, they can be taken away for bad behaviour) can cause problems with precise technical equipment that require time to be, you know, consistent. Hilariously, the effect is not dissimilar to what doom-criers said would happen during Y2K (remember that? Jesus, that was crazy, right?). When the last Leap Second was added in June 2012, reddit crashed and Gawker blacked out. So at least nothing important was affected. All this just goes to show that the made up system we use to track days and hours and seconds is faulty and needs to be replaced with something better. I myself have developed a 13 month calendar that disregards leap seconds and years and actually moves against "natural time" over the course of decades and centuries (happy 34th of Farnum everybody. It won't be summer again until your grandchildren are all dead).
I also highly recommend heading over to spendyourleapsecondhere.com. It is easily the best way to waste five to thirty minutes of what was meant to be time planning Cheryl's birthday party in the conference room. But let's be honest here: Cheryl is terrible, and internet videos are hilarious. So I think we all know who is coming out ahead on this deal. Worry about Cheryl tomorrow. If you've got a second.