February, with its 28 days (or 29 in a leap year), stands out as the only month with fewer than 30 days. This begs the question: why does February have the shortest month? The answer lies in Roman superstition and the evolution of the calendar from a 10-month system to the 12-month Gregorian calendar we use today.
Calendar showing the month of February
The original Roman calendar had only 10 months, six with 30 days and four with 31 days, totaling 304 days. To better align the calendar with the lunar year, King Numa Pompilius added January and February. He also altered the lengths of the existing months, driven by the Roman superstition that even numbers were unlucky. He reduced each 30-day month to 29 days. This left him with 56 extra days to allocate to the two new months.
Since the lunar year is approximately 355 days, Numa needed the total number of days in the calendar to be odd. Because adding an even number of odd numbers always results in an even sum, at least one month had to have an even number of days. February was selected as the “unlucky” month to have 28 days, potentially because it was associated with rituals honoring the dead.
Further modifications were made to the calendar over time, including adjustments to February’s length, the introduction of a leap month, and eventually the modern leap day. Despite these changes, February’s 28-day length has persisted, a lasting reminder of ancient Roman superstitions and the complexities of calendar development.
