How to Calculate Leap Year and Why it Exists in the First Place

4. How did February become the shortest month?

Augustus is also the reason that February is the only month with fewer than 30 days. July is a month named after Julius Caesar, as it was the month that the emperor was born in. The month was originally named Quintilis, and Sextilis was to be the month renamed in honor of Augustus.

Yet July had 31 days, and originally August only had 30 days, which would have been seen as a slight on the emperor. To appease this and highlight Augustus’ importance, the Romans borrowed a day from February. This meant in a leap year there were only 29 days, and therefore 28 days in a common year.