February

February is named for the Latin word februum which means purification. It is the shortest month, always lasting less than 30 days. It did not actually join the calendar until 713 BC, and was actually the last month (following January) until about 450 BC when January and February were moved to the beginning of the calendar.

The number of days in February varied between 23 and 27 days to account for the precession of the equinox and did not have the length of 28 days until the Julian calendar was established under the rule of Julius Caesar. Leap days were added every four years to account for the orbit of the Earth around the Sun, which was approximately 365.25 days (it is actually 365.2425 days and created problems in the 1580s which we will discuss later).