Time, man. You think you get it. And then you realize that the Ancient Greeks and Romans were so calendar-challenged that they had to insert random months every few years to make sure the seasons lined up properly. Then you have the Gregorian calendar, and the day in 1752 when England the U.S. decided to adopt it, effectively losing 11 days all at once. It's kind of insane. (You may have also heard that Samoa just decided to switch time zones, and Samoans didn't get a Friday. Like today didn't exist for them, at all.)

Anyway, please enjoy this informative video about the history of the calendar, and why we start our year on January 1st. [via Laughing Squid]