Why February Only Has 28 Days
Feb 26, 2015
The Julian system was fairly accurate, but its estimate of the length of a year was about 11 minutes too long. Over about 1200 years, this led to the calendar being off by about 10 full days. In order to permanently affix Easter with the spring equinox, Pope Gregory recalculated the calendar again, and that's what we use to this day.
Poor February. As this video shows, it seems that historically speaking, February has always been the month that gets messed around to make room for the others. This video gives a great historical account of how leap days came to be, but it stops at the Julian calendar. It does, however, briefly mention Pope Gregory, the man to whom we owe our calendars today.