Every time February rolls around, the same couple of thoughts go through our heads. First, we wonder how we didn’t notice that first r in February until we were well into elementary school. Then we wonder why February only has 28 days (except when it has 29). Finally, we tell ourselves we don’t have time to think too much about how strange this month is. Luckily, we had time to find the answers to these questions. The first one about “Feb-yu-ary” is simply because our brains don’t like words having too many r’s in close proximity, which is why we also forget the first r in surprise (and February coming right after January probably doesn’t make it any less confusing). The calendar question, however, is a lot more complicated.

In the Beginning

Making a calendar is hard. There’s no time to go through the entire history of calendar-keeping in this article, but suffice it to say, by the 8th century BCE, the Romans thought the best way to structure a calendar was around the lunar cycles. This format is also known as a lunar calendar, a structure used by many world cultures throughout history. The old Roman calendar was unique as it only had ten months, March through December. These months were mostly the same as they are today, save for December and what is now July both only having 30 days. But what about the rest of the year? Well, what about it? That’s how they’d probably answer. They viewed the wintertime as so worthless that historians today think they may have genuinely just not recorded the dates of the days before the spring equinox. Winter was no use to the farmers that fed Rome, so one-sixth of the year simply did not get to be part of any named month as far as we know.

The First Fix

Originally slotted at the end of the year, January and February first showed up when ruler Numa Pompilius reformed the calendar, basing it around the lunar model. But this posed a few problems. First, superstition made a mess of things. The Romans believed even numbers were unlucky (yes, half of all numbers were unlucky to them). Unfortunately for Numa Pompilius, there are 12 lunar cycles in a year across 355 days, and 12 odd numbers will always add up to an even number. So, to arrive at 355 days, every month had either 29 or 31 days, except for February, which got saddled with 28. February took one for the team. But what about the other ten days to make it 365? Say hello to the leap month. This was “Intercalaris,” or more commonly “Mercedonius.” This 13th, 27-day month was added every few years to balance the calendar and the seasons. Interestingly enough, when Mercedonius occurred, it took the last few days of February with it, shortening it even further to 23 or 24 days.

The Second Fix

Mercedonius wasn’t just confusing; it was socially problematic. The powers-that-were somehow managed to use a calendar as a tool for political corruption. Religious leaders and politicians (who were often one in the same) implemented Mercedonius when they wanted to extend an ally’s term of office and skipped it to get their enemies out faster. By the time Julius Caesar came to power, the calendar was off by months. Caesar implemented a new calendar based on the solar model of 365 days. In 46 BCE, “the year of confusion,” the calendar was temporarily stretched to recalibrate the seasons by adding two leap months for a total of 455 days. Then it was January 1, 45 BCE (or to the Romans, January 1, 709), and the rest is history. The Julian calendar dominated Europe until the 16th century and was still used by some countries like Russia and Turkey until a century ago. It’s still used by some religious groups today, such as Eastern Orthodox Christianity and the Amish. In all the fuss, however, Julius Caesar neglected to extend February. It was still 28 days.

The Best Fix So Far

To reiterate: making a calendar is hard. Julius Caesar included a leap day for every fourth February because he knew one solar year was not exactly 365 days. Therefore, he made a calendar that would average out to 365.25 days. Except a year is actually more like 365.2422 days. Oops. As the centuries passed, the calendar was slowly but surely becoming misaligned again. That’s why in 1582, Pope Gregory XIII, after having a bunch of mathematicians pore over the problem for years, had ten days in October outright skipped to get back on track, and put in a new system where February would have a leap day every four years except in years divisible by 100 unless it was also divisible by 400 (which is why we had a leap year in 2000). Some non-Catholic-ruled countries held out on accepting the Pope’s new calendar for quite a while; even the earliest American colonies used the Julian calendar. But after a few centuries, the Gregorian calendar became the European standard, and then the world secular standard soon after that. The modern Gregorian calendar is still not a perfect structure, but it’ll be a couple millennia before we’ll need to work out the kinks again. So, why is February set up the way it is? It’s the product of a long line of fixing oversights in designs meant to fix other oversights.