Odd little February is the shortest month of the year. Historians aren’t exactly sure just why that’s the case. But tracing its evolution gives us a capsule history of the evolution of the calendar.

The modern western calendar is a descendant of the earliest Roman calendar. It included only 10 months, beginning with March. The months were followed by about 60 days that weren’t part of any month.

That system didn’t work very well, though, so two months were added to the end of the year – January and February. Eventually, they were shifted to the start of the year.

The lengths of the 10 original months were changed to leave 56 days for the newcomers. But the Romans feared even numbers, so they added a day to January to give it 29. February was the month for festivals of repentance and for honoring the dead, so it stayed an unlucky even number.

But this version of the calendar contained only 355 days. So an extra month was added every other year. In those years, the last five days of February were dropped.

After that, February remained unchanged until 46 B.C., when Julius Caesar introduced the basic calendar that’s in use today. He named the seventh month for himself: July. And he might have lengthened February to 29 days. If so, it was cut back to 28 by Augustus Caesar, who took the extra day for the month that bears his name: August.

Script by Damond Benningfield