New Year's Day: Why Does the Calendar Change on January 1?

'Tis the season for reading flurries of year-end round ups, stocking up on champagne, and planning lofty resolutions you'll inevitably break just a couple of short weeks into January—that's right, New Year's is coming. But why? The new year has to begin sometime, but why pick January 1?

Unlike the seasons and certain holidays, which are tied to astronomical phenomena, New Year's Day is a purely human artifact. Of course, it reflects a real astronomical fact: Earth traces a complete orbit around the sun once every 365.25 days. But there's nothing celestially special about January 1—March 6 or August 24 would do the trick just as well.

12_28_new_year_day Times Square is already getting ready to ring in the new year—but why celebrate now? Drew Angerer/Getty Images

Most of the world goes by the Gregorian calendar, which Pope Gregory established through a papal bull in 1582. The scheme aimed to solve liturgical problems surrounding the date of Easter. The calendar was only adopted gradually, causing a series of discrepancies as, for example, Italy converted in 1582, England in 1752, and Russia in 1918.

But the roots of marking the new year on January 1 go farther back even than Christianity. Julius Caesar in 46 B.C. took it upon himself to try to sort out the deeply complicated Roman calendar, and his solution, which stuck despite his assassination, included beginning the year on January 1. That was in part on account of January's namesake, the god Janus, who oversaw beginnings.

But after Christianity came into popularity, Europe saw many centuries of backlash against so-called pagan traditions like those established by Caesar. So dates like Christmas and March 25, also known as Lady Day or the Feast of the Annunciation, were officially used to mark the new year, although January 1 was still a popular day for less formal celebrations and regained its status with Gregory's reform.

Read more: New Year's Day Super Moon: What Is the Wolf Moon and When Is It Happening?

Of course, January 1 still hasn't quite nailed down its exclusive status as the first day of the new year. In China, the new year is celebrated between January 21 and February 21 based on the lunar cycle. The Hebrew calendar begins in the fall. Pre-Christian inhabitants of Britain used the winter solstice. Every option gets the job done.

Despite everyone's comfort with the calendar as it currently stands, some would still like to see it change. One pair of men have spent more than six years lobbying for a tweaked calendar that would maintain January 1 as the first day of the year but chop the year off after a round number of weeks. It's likely to stick just as well as your resolutions.