February is the only month in the year with just 28 days — or 29 in the leap year. But very few people know why this is. While it is mostly chalked up to having something to do with the earth’s rotation around the sun, Indianapolis Children’s Museum’s website tells us about its history. The 28 days month is traced back to Numa Pompilius, the second king of Rome.
The Initial Calendar
Before his reign, Rome’s lunar calendar had only 10 months, from March to December. This is because Romulus, the first king of Rome, and his people did not include the time between December to March as it was not important enough in terms of the harvest to be included in the calendar. When Numa took the throne, he tweaked the calendar to be lined up with the 12 lunar cycles in the year. The new 355 day year needed two more months to make up for lost time leading to the new months of January and February.
Why February?
Romans saw even numbers to be unlucky, so the months had to have an odd number of days, 29 or 31. Still, to reach the 355 number of days, one of the newly added months had to be even, which ended being February. It has also been claimed that February was chosen due to the fact that Romans honored their ancestors and performed purification rites in this month. When the new calendar came into use, its practicality was questioned when the seasons and months fell out of sync.
Final Solution
When the issues still persisted after the amendments, in 45 BC, Julius Caesar brought in an expert to replace the lunar calendar with a sun-based one like the Egyptians. This led to an addition of 10 days to every year, making all months 30 or 31 days long, leaving February with 28. To align Rome as per the Julian calendar, 46 BCE had to be 445 days long.