Why is New Year’s Day on January 1?
It’s a calendar choice, not a natural one. Rome’s officials began taking office on January 1 around 153 BCE, Julius Caesar’s calendar made it the start of the year, and Britain didn’t switch until 1752.
Quick Answer
January 1 has no astronomical meaning. It isn’t a solstice or an equinox; it’s a date people chose. The Romans began their consular year on January 1 around 153 BCE, reportedly so new consuls could take charge sooner during an uprising in Spain. Julius Caesar’s Julian calendar, which took effect in 45 BCE, then made January 1 the start of the civil year. In the Middle Ages, much of Europe counted the new year from other dates, such as March 25. The Gregorian calendar that Pope Gregory XIII introduced in 1582 also begins the year on January 1, and Catholic countries adopted it first. Great Britain and its American colonies kept March 25 until 1752, when a new law moved New Year’s Day to January 1 and skipped from September 2 to September 14. The month itself is named for Janus, the Roman god of doorways and beginnings.
By the Numbers
Key Facts
- Why January 1
- A date people chose, not a solstice or an equinox
- Rome
- Consuls began taking office on January 1 around 153 BCE
- Julian calendar
- Took effect in 45 BCE with January 1 as the start of the year
- Britain and its colonies
- Switched in 1752, moving New Year’s Day from March 25 to January 1
Timeline
- About 153 BCE
Roman consuls begin taking office on January 1 instead of March 15.
- 45 BCE
The Julian calendar takes effect, with January 1 as the start of the civil year.
- 1582
Catholic countries adopt Pope Gregory XIII’s calendar; October 4 is followed by October 15.
- 1752
Britain and its colonies adopt the Gregorian calendar; September 2 is followed by September 14, and the new year moves from March 25 to January 1.
A military crisis moved the date
Roman sources say the consuls, the republic’s top officials, once took office on March 15. Around 153 BCE, an uprising in Spain led the Senate to move the start of their term to January 1 so they could get to work sooner. The date stuck, and when Julius Caesar reformed the calendar in 45 BCE, January 1 became the first day of the civil year.
A slow, patchy switch
After Rome fell, different places started the year on different days, including March 25, which celebrated the Annunciation. Pope Gregory XIII’s 1582 reform fixed the calendar’s drift against the seasons and began the year on January 1. Catholic countries adopted it first. England and its colonies stayed on the old Julian calendar and a March 25 new year until 1752, when 11 days were skipped to catch up.
A god with two faces
January is named for Janus, the Roman god of doorways, gates and beginnings, often shown with two faces looking forward and back. It’s a fitting name for the month that opens the year.
Myth vs. Fact
MythNew Year’s Day is January 1 because of an astronomical event.
FactIt isn’t tied to a solstice or an equinox. It’s a calendar convention that Rome adopted and later calendars kept.
MythBritons rioted over “Give us our eleven days” when the calendar changed.
FactHistorians have found little evidence of calendar riots. The slogan appears on a banner in William Hogarth’s 1755 election satire, which may have started the myth.
The Bottom Line
New Year’s Day is January 1 because Rome began its official year then, and the calendars that followed kept the date. Britain and its American colonies didn’t switch until 1752.