Thirty days hath September,
April, June, and November;
Thirty-one the others date,
Except in February, twenty-eight;
Why twenty-eight? No one knows,
Perhaps to keep us on our toes!
The history of how February came to have 28 days is a long and confusing one. The Roman calendar was first created by Romulus, the founder of Rome. This 8th century calendar only had 10 months, starting in March and ending in December (no need to name those pesky days when neither planting nor harvesting were going on in an agrarian society). This makes perfect sense when you think of the Latin prefixes sept, for September the (7th month), oct for October (the 8th month), and dec for December (the 10th month). We are used to seeing these prefixes in words like septuplets, octagon, and decimal.
Romulus’s successor, King Numa Pompillious, decided that it made more sense to align the calendar with the moon’s cycles, which meant two more months, January and February, had to be added. His calendar, which had 355 days, featured odd numbers (considered lucky), except for one month which had to be even to make the math work. He put January and February at the beginning of the year, forever misaligning the months from their ordinal names. This worked for a while, until the calendar had to be realigned with the seasons. Then a 13th month called Mercedonius would be inserted, shortening February even more to 23 or 24 days. This made the year 377 days long. Given the inconsistent nature of Mercedonius’s placement, which was decided by the Roman High Priest, this made for some major confusion (and you thought it was bad to be born on leap day!). Just imagine waiting for an announcement from the Pope to find out what day it was.
Enter Julius Caesar, who decided not only was a new, solar-based calendar a good idea, but that the year should have 365 days, with an extra one thrown in every four years. That meant he had to decree a one-time 445 day year to recalibrate to the new calendar – a small price to pay for ending the perpetual confusion.
It is possible the Romans wanted the religious ceremonies that occurred in February, the month of sanctification, to be shorter, or that Julius Caesar’s successor, Augustus Caesar, wanted the month renamed after him, August, to have at least as many days as Julius Caesar’s July. Whatever the case, February remained a shorter month. Under the Julian calendar February had 29 days, or a leap day, only if the year was divisible by 4. The Julian calendar survived until the Gregorian calendar came along in the 1500s. A few adjustments were made to make leap year more precise, and the modern calendar was born. Leap day is still used as an intercalation, extra time inserted to align the year with solar or lunar activity. And while the calendar we use today is still off by 1 day every 3,236 years, it’s accurate enough. No one wants to fiddle with it, even if it means February remains a short month.