Thanks to Pope Gregory XIII, we now have a calendar that accounts for equinox inconvenience that would have eventually landed Easter in the chilly winter months. It’s called the Gregorian Calendar, and it takes the previous standard (the Julian calendar) and makes the year 0.0075 days shorter.

(that’s all you need for Quizzo, but here’s more fun facts):

It does this by adding February 29th every four years, unless the year is divisible by 100 (1700, 1800, 1900, etc), unless* *it’s *also *divisible by 400 (such as 2000). It made the calendar year 365.2425 days long (as opposed to the 365.25 of the Julian standard), which is as close to the 365.2422 day standard we actually have. This part isn’t on Wikipedia, but I’m pretty sure if you follow the math out, we’ll need a February 30th within the next couple of millenia.