December 21 is day 355 of the year (356 in a leap year). The Sun is then roughly 30° into Sagittarius, on the last day before it moves into Capricorn, which places your birthday in the third of the sign’s three decans.
Sagittarius, third decan
Sagittarius closes with a decan colored by Leo, whose radiant creativity warms Jupiter’s optimism. You are Sagittarius with a performer’s warmth. You tend to light up rooms with storytelling, humor, and generosity. Creativity and self-expression feel essential to you. Your optimism inspires others, and you enjoy sharing your discoveries widely. Pride may surface when you feel unappreciated, yet your big heart and joyful spirit make you a beloved presence wherever you roam.
Cusp of Prophecy: the Sagittarius–Capricorn cusp
Optimistic Sagittarius runs into disciplined Capricorn, so you may dream on a grand scale and then sketch a sensible plan to get there. Vision and realism keep each other honest. The Sun at your birth was in a single sign; still, the cusp is a handy way to describe that combined flavor. Check your exact Sun sign with the big three calculator.
Born on the 21st: birthday number 21
A 21st birthday puts partnership first and initiative second, and the pair settles into three, the number of joy and expression. You are usually sociable, witty, and inventive, especially when collaborating. People often find you inspiring and fun to be around. A group project with you in it rarely runs short of ideas. You love starting conversations and bringing people together. Your challenge is staying grounded and finishing projects when new social opportunities or exciting ideas keep calling your name.
2 + 1 = 3: The Communicator. Think of your 3 as a splash of color mixed into a bigger painting. Your life path number, the sum of the day, month and year you were born shrunk to one digit, is the canvas. Your playful, talkative side may lead that story, or simply add the sparkle. Calculate your life path number.
Your birth tarot cards
Temperance, the card of Sagittarius. It belongs to the archer, who aims at distant goals. The card’s angel blending waters suggests the sign’s search for meaning, its optimism and the art of combining experiences into wisdom.
Ten of Wands, the card of your decan (Saturn in Sagittarius in the Golden Dawn system). Put down at least one load that isn't yours to carry.
The World, the card of your day number. A dancer framed by a wreath, it stands for wholeness and the satisfying sense of a cycle complete. It hints that every ending you reach also opens the next, larger circle. Finish what you started and enjoy the moment of completion.
The card of your whole birth date, year included, comes from the tarot birth card calculator.
Strengths and challenges
Strengths: creative storytelling, warm generosity, sociability, inventiveness, honesty. Growth edges: craving for applause and inconsistency.
Love and compatibility
Romance for you is celebratory and generous. You love grand gestures and a partner who enjoys life as fully as you do. Mutual admiration and shared adventures keep your relationship vibrant and joyful.
Playful, affectionate, and communicative, you enjoy a relationship full of laughter and shared adventures. You value a partner who listens. Deep talks matter as much as fun dates in keeping your bond strong.
Signs that often click with Sagittarius: Aries, Leo, Libra, Aquarius. Compare any two signs.
Career and purpose
Entertainment, teaching, publishing, event planning, marketing, and travel media all give your creativity a visible outlet. Audiences tend to lean in when you speak. Let your creativity shine, and balance self-expression with collaborative listening.
Communications, entertainment, events, marketing, and teaching suit your social creativity. You work best in teams that brainstorm freely. A reputation for results grows when the follow-up matches the brainstorm.
Born in December
December arrives with twinkling lights, the darkest evenings of the year and a calendar packed with holidays and gatherings. Its birthdays share that generosity and the promise that light returns. Turquoise, tanzanite and zircon gleam in wintry blues, while narcissus blooms indoors and holly brightens doorways with glossy green and red. Birthstone: turquoise, tanzanite and zircon. Birth flower: narcissus and holly.
Affirmation for December 21
I share my joy and follow through.
Frequently asked questions
What zodiac sign is December 21?
Sagittarius, third decan. It sits on the Sagittarius–Capricorn cusp, so check the birth year and time.
What is the tarot card for a December 21 birthday?
Temperance for Sagittarius, the Ten of Wands for the decan, and The World for the day number 21.
What is the birthstone for December 21?
Turquoise, tanzanite and zircon, with narcissus and holly as the birth flower.