December birthdays

December 21 zodiac sign

By Maren Tremblay, Fatesight editor · Last updated October 30, 2026

December 21 is Sagittarius: at noon UTC on this date from 1950 to 2010, the Sun stood between 28°48' Sagittarius and 29°59' Sagittarius, in the third decan, with the constellation Sagittarius behind it.

The years the Sun changed sign on December 21

The Sun moved from one sign to the next on this date in 25 of the 61 years. If you were born on one of these days, your birth time decides your sign: 1952 at 21:43 UTC, into Capricorn, 1956 at 20:59 UTC, into Capricorn, 1960 at 20:26 UTC, into Capricorn, 1964 at 19:49 UTC, into Capricorn, 1968 at 19:00 UTC, into Capricorn, 1972 at 18:13 UTC, into Capricorn, 1976 at 17:35 UTC, into Capricorn, 1977 at 23:22 UTC, into Capricorn, 1980 at 16:56 UTC, into Capricorn, 1981 at 22:50 UTC, into Capricorn, 1984 at 16:23 UTC, into Capricorn, 1985 at 22:08 UTC, into Capricorn, 1988 at 15:28 UTC, into Capricorn, 1989 at 21:22 UTC, into Capricorn, 1992 at 14:43 UTC, into Capricorn, 1993 at 20:26 UTC, into Capricorn, 1996 at 14:06 UTC, into Capricorn, 1997 at 20:07 UTC, into Capricorn, 2000 at 13:37 UTC, into Capricorn, 2001 at 19:21 UTC, into Capricorn, 2004 at 12:41 UTC, into Capricorn, 2005 at 18:35 UTC, into Capricorn, 2008 at 12:03 UTC, into Capricorn, 2009 at 17:46 UTC, into Capricorn and 2010 at 23:38 UTC, into Capricorn.

What the third decan of Sagittarius is read as

The third decan of Sagittarius is read as carrying a touch of Leo and the Sun. It is the Sagittarius with a sense of occasion. People here tend to tell the story better than it happened, to love warmly and in public, and to want work that gets noticed as well as work that matters.

What the number 3 adds

Numerology reads a birthday that comes to 3 as the mark of a talker and a maker. It tends to mean an easy way with words, a need to express what you feel, and some trouble finishing what stopped being fun.

The sky on December 21, 1950 to 2010

Mercury: Sagittarius in 33 and Capricorn in 28 of 61 years. Retrograde in 1951, 1957, 1964, 1970, 1971, 1977, 1984, 1990, 1997, 2003 and 2010. Mercury in Sagittarius.

Venus: Scorpio in 16, Aquarius in 16, Sagittarius in 15 and Capricorn in 14 of 61 years. Never retrograde. Venus in Scorpio.

Mars: Scorpio in 9, Sagittarius in 8, Libra in 7, Capricorn in 7, Aquarius in 7, Pisces in 5, Aries in 4, Virgo in 4, Taurus in 3, Cancer in 3, Leo in 3 and Gemini in 1 of 61 years. Retrograde in 1960, 1975, 1977, 1990, 1992, 2007 and 2009. Mars in Scorpio.

New Moons: 1957 and 1976. Full Moons: 1980, 1991 and 2010. Lunar eclipses: 1991 (partial) and 2010 (total).

Every year's sky on December 21

At noon UTC. R: retrograde.

Who you tend to match with

Sagittarius: closest Aries, Leo and Libra; hardest Pisces. Its third decan leans Leo. All twelve.

How we calculate the sky

• December 20
• December 22
• December zodiac signs
• Sagittarius
• Birth chart calculator