Monday is a day that only comes around every four years: February 29th, or Leap Day. You know that we have Leap Day to sync up the number of days in a year, because the earth revolves around the sun every 365.25 days. We add an extra day every four years to make up that .25 of a day. The ancient Romans figured it out, and revamped the calendar a few times to get it right. Other weird things went into those calendar-making days.
And have you ever wondered why February is shorter than every other month? That's also because of Augustus. The Roman Senate, to honor him, renamed the month of Sextilis as Augustus (August). But originally August was only 30 days long, and this was a problem because Julius Caesar's month (July) was 31 days long. It wouldn't do for Augustus to have a shorter month than Caesar!
To make August as long as July they borrowed a day from February, reducing it from 30 days during a leap year to only 29, and 28 days every other year. This permanently left February as the odd, shortened month that it is.
Learn more weird tidbits about our calendar and the extra day at About Entertainment. -via Boing Boing
(Image credit: One Day Calendar Generator)