Like, seriously, people notice "OCTOber" and "DECEMber" and say, "hey, those mean 'eight' and 'ten', but they're the 10th and 12th months, what's up with that?".
If you've got a little more history, you'll know that July and August are named after Julius and Augustus Caesar, and think, "oh, they added those two months and bumped the rest of the months back."
Nope. The Romans were way, way worse at calendars than that.
July and August were actually originally Quintilis and Sextilis - the fifth month and the sixth month. They were called this because the year traditionally started in March. So they had Martius, Aprilis, Maius, Junius, Quintilis, Sextilis, September, October, November, December.
Martius was named for Mars; Junius was named for Juno. We have no idea what Aprilis and Maius were named after. (No, really.) Then they got lazy and just numbered the months.
"But wait," you ask, "what about January and February?" Hold onto your butts, because calling the months by their numbers? Not even close to the laziest the Roman calendar got.
Between the end of December and the beginning of Martius were 50-odd intercalary days. They didn't HAVE months associated with them. They were just sort of there.
I swear I am not making this up.
In addition, each month had either 30 or 31 days. I was going to say "alternated between" but I looked it up and nope, the Romans decided that was too easy, so it actually went:
Okay. This is where we are at the beginning of the Roman Republic.
Look at that. Remember it. You will look back on this and say "actually, that makes sense" after what comes next.
At the beginning of the Roman Republic, the Senate decided to fix the calendar. This was for two reasons:
1) The Romans thought the Greeks kicked ass, and wanted to emulate their calendar.
2) Count those days. You will notice that they add up to 355, which means that each year is actually ten (and change) days /shorter/ than an actual solar year - which meant that by the time of the Republic, March was somewhere in the autumn.
So the Senate decided to do some reforming. They added two brand-new months to the calendar, Januarius and Februarius. Januarius was named after Janus, because his holiday fell about a week into the new month. (Janus was the god of doorways. We'll come back to him.) February was named after the Februa, a feast that fell in the middle of the new month and that had, in fact, long since been replaced by Lupercalia, an identical feast on the same date with a different name For Reasons.
The Senate also added an intercalary month, Mercedonius, the Month of Wages.
Yes, an intercalary month. I want to make sure that's clear.
They also changed the lengths of the months to better fit the Greek system. The Greeks had largely lunar months, so they alternated between 29-day and 30-day months. Once again, the Romans said, "you know, we like this, but it's too easy".
Look, the next post is going to go into "what the hell was WRONG with them?" territory, just warning you.
This is the calendar the Roman Senate ended up with:
THE REST OF FEBRUARIUS NO I AM NOT KIDDING 5
See what I meant about Mercedonius being an intercalary month? It's literally in the middle of February. Like, they got 3/4 of the way through February, got bored, and decided to do something else for a month and come back later.
Also, the Romans had caught on to leap years by this point, so every fourth year, Februarius had an extra day on the end, bringing its total to 29.
I want to be clear, though, that while they'd caught on to leap days, they STILL had not caught on to the length of the damn year. Count those days again: it's 378. By the time of poor Gaius Julius Caesar in 46 BC, the calendar was so fucked up that he needed THREE intercalary months to right it again.
The Julian reform - which was ordered by our friend G.Jiddy but not, as far as we know, actually created by him - did three important things.
First, it added those three intercalary months to put the year back where it was supposed to be (March had slid around to the dead of winter).
Second, it got rid of Mercedonius, putting the year back at 355 days.
Third, it scattered ten new days throughout the year, which gave us the calendar we know today.