What Zodiac Signs Are in December? Sagittarius and Capricorn
December holds two zodiac signs: Sagittarius through the solstice switch on December 21 or 22, then Capricorn after it.
December 1-20 and December 23-31 are settled in every year our table resolves; only the two switch days need a birth year.
I give you the pattern here, while the checker handles your year and the stubborn "December 22" convention. You can also see all 12 signs by month.
December Has Two Zodiac Signs: Sagittarius, Then Capricorn
Sagittarius holds roughly the first three weeks of December, while Capricorn takes the last nine or ten days. Put plainly, most of December is Sagittarius.
For the precise boundaries published elsewhere on this site, see Sagittarius's exact dates by year and Capricorn's exact dates by year. Those pages cover the individual signs; this one stays focused on placing a December birthday.
Which sign a December birthday falls under
| Birthday | Zodiac sign | What decides it |
|---|---|---|
| December 1-20 | Sagittarius | Settled in every year our table resolves |
| December 21 | Sagittarius or Capricorn | The birth year decides, and if the switch falls that day, the hour does |
| December 22 | Capricorn in every recent year; the switch could fall here in older years | Your birth year, and then the hour |
| December 23-31 | Capricorn | Settled in every year our table resolves; the season continues into January |
The middle two rows are the reason I will not label a bare December 21 or December 22 birthday. Those dates sit around a moving boundary, not a fixed midnight cutoff.
The December Switch Is the Solstice: December 21 or 22
Capricorn does not start on a date somebody picked. It starts at the December solstice, one of four seasonal markers that anchor the tropical zodiac. The other three open Aries at the March equinox, Cancer at the June solstice, and Libra at the September equinox.
That point reframed the boundary for me. Once I understood that the sign opens at an astronomical moment rather than on a chosen calendar date, a two-day window stopped looking sloppy and started looking honest.
The seasonal marker is an astronomical moment and the calendar is a counting system, so the two drift against each other; the full mechanism belongs in why the solstice date itself moves.
For December, the usable window is December 21 or 22, depending on the year. Both dates are normal. On whichever day contains the switch, the hour of birth decides whether the Sun had entered Capricorn yet.
That is why "born December 21" is not enough information on its own. The year identifies the relevant solstice, and the hour settles a birthday that falls on the switch day.
Dates on this page use US Eastern time; in UTC and European local time, the same moment prints as December 22 in some years, including 2019 and 2023 in our table, and the checker displays both dates. For your own result, check your exact birth year.
Why Almost Every Chart Says "December 22"
"December 22 - January 19" appears on mugs, in birthday books, and across countless printed date charts. That range was not invented. Across 1900-2030, our table resolves 129 years in US Eastern time, with an almost even split between December 21 and December 22.
The timing is not evenly scattered, though. Every December 22 switch in the resolved table is in the past. The last occurred in US Eastern time in 2011, and every resolved year from 2012 onward lands on December 21.
I went into our table expecting December 22 to be the ordinary case because that was the range I grew up seeing in print. Instead, I found that the mug was describing a calendar that had already moved on. A shorthand that has missed every resolved US birth since 2011 has stopped being useful shorthand.
Myth vs. fact
Myth: Capricorn starts December 22.
Fact: In US Eastern time, the switch has not landed on December 22 since 2011. Every resolved year since then has placed it on December 21.
Myth: Zodiac dates are fixed, so the printed range must be right.
Fact: This boundary is the December solstice, an astronomical moment rather than a chosen date. The printed range froze decades ago; the seasonal marker kept moving against the calendar.
Myth: December is a Capricorn month.
Fact: Most of December falls under Sagittarius. Capricorn gets the final nine or ten days, then its season continues into January.
Which day the switch actually landed on, 1900-2030
| Switch day (US Eastern) | Years out of the 129 the table resolves | When it happens |
|---|---|---|
| December 21 | 66 | The only case in every resolved year since 2012 |
| December 22 | 63 | Common through much of the twentieth century; last seen in US Eastern time in 2011 |
Two years within the covered range are still pending double-sourcing, so I use "every year the table resolves" rather than claiming a result for every year through 2030. Readers who want the underlying year-by-year material can use Capricorn's exact dates by year.
Which Sign Is My December Birthday?
Treat December birthdays as four cases. Most require no calculation, while the two boundary dates need more information.
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Born December 1-20: Your Sun sign is Sagittarius in every year our table resolves. No lookup is needed.
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Born December 23-31: Your Sun sign is Capricorn in every year our table resolves. No lookup is needed, and the season carries into January.
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Born December 21 or 22: Your birth year decides which date held the switch. Put the date and year into the calculator to check your exact birth year.
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Born on December 21 or 22 without a known birth time: The honest answer stays open if your birthday was the switch day. The checker shows the switch moment for that year, so you can see what the missing hour would settle.
I do not use "probably" for a boundary birthday. If the hour decides, guessing from a generic date range only replaces missing information with confidence. The guide for anyone born on a boundary day explains how to handle that uncertainty without pretending two signs overlap.
What the Month Alone Does Not Tell You
Knowing that December runs from Sagittarius into Capricorn tells you which date page to consult. It does not produce a personality readout.
Traditional symbolic descriptions are for entertainment and self-reflection, not science; a Sun sign is one part of a much larger chart. I don't read daily horoscopes - I like the zodiac as a mirror, not a map. That means I can find a description interesting without treating it as a verdict about somebody I know.
If you want the traditional sign descriptions, use the linked Sagittarius and Capricorn pages. If you want the limits stated without a sales pitch or a fight about belief, read what astrology can and can't tell you.
What Comes Before and After December
Sagittarius begins in November, and November's Sagittarius half covers that side of the season without repeating its boundary here.
Capricorn is the only sign whose season crosses the calendar-year turn, so the season starting in December does not end on December 31; continue with Capricorn's other half, in January.
For the broader calendar rather than one neighboring month, see all 12 signs by month.
December Zodiac FAQ
Is December 21 a Sagittarius or a Capricorn birthday?
It depends on the birth year, and if the solstice switch falls on December 21 that year, the birth hour decides too.
December 21 holds the switch in every recent resolved year, which is exactly why the date alone is insufficient; check your exact birth year for the relevant boundary.
Is December 22 a Capricorn birthday?
In every recent resolved year, yes, because the switch was already complete by December 22. Older birth years can still be in question because the switch itself last landed on December 22 in US Eastern time in 2011, so check your exact birth year.
Why do so many charts say Capricorn starts on December 22?
December 22 was the ordinary switch date through much of the twentieth century, and the printed range stuck. The underlying solstice shifted against the calendar, but the mugs and birthday books did not follow.
Does Capricorn season end when the year does?
No. It opens at the December solstice and runs past New Year's to the January 19-20 switch, making it the only zodiac season that crosses the calendar-year turn; follow Capricorn's other half, in January.
What does the winter solstice have to do with my zodiac sign?
Capricorn begins at the December solstice, not merely near it, because it is one of four signs pinned to a seasonal marker rather than a date somebody chose. That is a calendar fact; what the sign is said to mean comes from tradition, not science, as I explain in what astrology can and can't tell you.
Sources and What This Page Is
These dates come from the site's canonical ingress table, built from the astronomical and astrology-reference sources listed here and refreshed annually.
If your birthday lands on December 21 or 22, put your birth year into the checker - it takes ten seconds and settles the argument; if it doesn't, you already have your answer above.
Sources
- U.S. Naval Observatory, Astronomical Applications Department - Earth's Seasons: Equinoxes, Solstices, Perihelion, and Aphelion, December solstice instants used in the Capricorn ingress rows, as of the site's 2026 canon build.
- Cafe Astrology - Sun sign cusp and ingress tables, curated US Eastern rows for the December switch from 2016-2030, as of August 18, 2026.
- timeanddate.com - December solstice tables, cross-check for the UTC column and December 21-22 date split, as of August 18, 2026.
This page gives a Western tropical zodiac calendar pattern, not a scientific assessment or a prediction about any person.