I've always considered the new year according to the western (Gregorian) calendar to be a bit arbetrary, and thus never made much of a deal out of December 31st or January 1st. I don't quite remember, but it seems like I heard somewhere that in the old Julian (Roman) calendar the New Year fell sometime in Spring. All this, of course, begs the question of when to celebrate such. And me being myself, I've looked into various other cultures (past and present) to see if I found any special insight into the matter.
Ususally I end up celebrating the New Year at Samhain, the classic never-sounds-like-it's-spelled Celtic holiday that has survived into modern times as Halowe'en. Apparently the ancient Celts considered that day to be the end of the year, as well as having some other interesting traits. (If a talking corpse asks you for water that night, you might want to politely refuse.)
And of course there's the well-known Chinese New Year, which tends to fall in February I believe. The equasion for it I believe is the first New Moon (or some lunar phase) after the Sun has entered the constellation Aquarius.
So far everything has seemed to flutter around the same general time of year, which makes sense for residents of the northern hemisphere, as the year is an annual solar cycle, and it's fairly intuitive to place an arbitrary stop/start point in the general vicinity of the darkest part of that cycle, the winter solstace. So, with four possible dates for a new year so far, the obvious question to ask is "What about the Southern Hemisphere?".
And the answer is "I have no idea". But I can rant on about two historic groups that ived in the Northern Hemisphere, closer to the equater.
Having done a little research into the ancient Babylonians, I can guess, based on what I've read, that they celebrated two "new years" in one year. One fell in spring and the other fall. Apparently this interesting arrangement has to do with the growing season of ancient Mesopotamia. (Think like modern Mesopotamia, but wetter and generally more liveable. Also fewer terrorists.)
And then, of course, there's the Mayans. Timekeepers extrordanairre. Every resource I've seen on the Mayans and their academics says they were obsessed with timekeeping, and "obsessed" is invariably the word used. They had about three different calendars running simultaniously, so I guess each could produce a "new year" per year, or maybe two if the math lined up just right. So, um, answer six, I guess.
You want to know, don't you. Of course you don't, but I'll tell you anyway.
First off there was the sacred calendar, known by scholars as the "Ritual Alminac", with 20 13-day months. Now if you've been doing your math just now you'll realize that's ony 260 days, not hardly a full Earth-year of 365.2-something days. You can see how two of those can start in a single solar year. The second calendar is now known as the "Vague Year", as the year added up to 365 days (18 months of 20 days each, +5 unlucky days tagged on the end). Apparently the Mayans were fully aware that the solar year actually had 365 days and change, but saw no need to tag in provisions for leap years, and so this calendar wasn't competely in synch with the year propor.
Running these two calendars together, you get something that repeats every 52 years. That 52 year cycle is known as the "Calendar Round" by archaeologists. It sounds like a nice working system, but it happened that the kings, like rulers in many literate societies, liked to keep track of their dynastic herritage, and apparently they didn't like the idea of things getting fuzzy if you look back more than 52 years past.
The obvious solution to this is to put numpers on your 52-year cycle. Kind of makes sense, yes? Calendar round 3 starts 106 years after calendar round 1. There's only one problem with the obvious solution: it's obvious. I imagine that, at least once, some scribe in training suggested this idiot-resitant solution to long-term timekeeping, and was laughed out of the academy for it. The proper Mayan thing to do is to come up with yet another independently running calendar system. This one we call the "Long Count".
From what I can tell, the long count consists of k'in (days), winal ("months", 20 k'in), tun (18 winal, or 360 days), k'atun (20 tun), bak'tun (20 of those), and up. According to one source, the next step up the 'sun', is 13 bak'tun. According to another, piktun (20 bak'tun, not 13), kalabtun, and kinchiltun all consist of 20 of the previous. I did some rough math, and apparently a kinchiltun is about three million years. Considering modern humans haven't existed for that long, I don't think there's much chance of getting confused as to dates on that calendar. Mayan society was not unified, so I'm guessing different city-states did it differently, and what calendar system is bigger than a (400-year) bak'tun isn't a topic of every day conversation.
And getting back to the discussion on new years, I found out the next changing of the tun is January 14th. (Bak'tun 12, k'atun 19, tun 16, winal 0, k'in 0). So, the short of all that ranting is that, if you miss the new year's celebration, you can thank the Maya for having another chance in two weeks. (And the Chinese for having a third chance after that. And the Babylonians for one some time in spring...) And if you're wandering where the new years are on the ritual alminac and vague years, my answer is "I have no idea". I only know about transcribing long count dates to the modern western calendar.
Finally, no discussion of Mayan writing would be complete without mentioning the fabled 2012 apocalypse. Here's the scoop. Apparenty the current period, which began August something or other, 3114 BCE, ends on the winter solstace of 2012. (Dec. 21st or 23d. I coud do the math and find out which but am too lazy). According to Mayan mythos, the end of each such cycle (new 'sun', I guess) is marked by a cataclysm that wipes out most of humanity. So, if you believe in that sort of thing, you might get back to work on that back yard bomb shelter you gave up on after the end of the Cold War. I also hear the events marking the change of cycles don't always fall on the exact day, so I'd recommend finishing that bomb shelder a bit early.
And I know from watching the Apocalypse Channel (which is also sometimes known as the "history channel") that that date is marked by a once-in-for-freaking-ever galactic alignment that Nostradamus made some predictions about, mostly of a grim nature. Also, I think it's supposed to be the Rapture. Apocalypse channel says so. (But then, people said that about the year 1000. They also said that about the year, um, 50 or so. The point is people have been waiting a long time for that one). Just to be on the safe side, I'd recommend stocking that bomb shelter with a bible. Actually, I'd throw in shrines and holy texts from a bunch of religions, just to make sure all my bases are covered. You never know.
So, is it possible to rent out bomb shelters, maybe in time shares or some such? We had a little bit of an apocalypse scare with Y2K. (Wasn't that supposed to be the Rapture?) If I had a bomb shelter I could have made good money renting it out to scared fundamentalists. Or during the financial crisis I could have probably made a lot of money renting one to some failed Wall Street tycoons (who are STILL rich). Hey, wasn't that... no, actually, I don't think that was supposed to be the Rapture. Why not, though? Everything else is.

