♐︎ Sun at ~26° Sagittarius · third decan · Saturn

December 18 zodiac sign: Sagittarius, third decan

If you were born on December 18, your sign is Sagittarius, the fire sign ruled by Jupiter: the Sun is in Sagittarius on this date in every year from 1980 to 2030. The Sun sits about 26° into Sagittarius on this date, in the third decan, where Sagittarius's core takes on a Saturn flavour. Here's what the date fixes, and what only your birth time can tell you.

Your sign: Sagittarius

The mutable fire sign that aims at the bigger picture and refuses to be domesticated.

A Sagittarius Sun is built around expansion and meaning. You're the friend who has lived in three countries, who keeps reading philosophy at 2am, who wants to know what people actually think rather than what they're supposed to say. Your optimism is real — not the brittle "everything happens for a reason" kind, but a genuine sense that life is interesting and worth showing up for.

The date fixes the Sun; the year and hour fix the rest. A Sagittarius born December 18 with the Moon in Libra runs on a different inner weather from one with the Moon in Sagittarius: see Sagittarius Sun, Libra Moon. Your rising sign needs the birth time; the twelve Sagittarius Sun combinations show what each one changes.

Sagittarius dates, traits & compatibility → · What a Sagittarius birth chart looks like →

In the US (2000–2014), an average of 12,061 babies were born on each December 18, rank 38 of 366 dates; Sagittarius is number 10 of 12 signs (7.95%). What's the most common zodiac sign?

The Moon on December 18, 1980–2030

Across the 51 years from 1980 to 2030, the Moon at noon UTC on December 18 was most often in Libra (6 years) and least often in Gemini, Leo, and Aquarius (3 years each). Unlike the Sun, the Moon sign depends on the birth year. On December 18, 2026, the Moon stays in Aries the whole UTC day.

In 24 of those 51 years (47%) the Moon changed sign during December 18 itself, so in those years the birth time decides the Moon as well as the rising sign. Cells with an arrow mark them, with the UTC time of the change. The Moon was exactly full on December 18 in 1994, and new in 1998 and 2017.

Find your birth year. One sign means the Moon spent the whole UTC day there; an arrow means it changed sign that day, at the UTC time shown: born before it, the first sign; after it, the second. The Moon sign calculator settles it in seconds; your birth chart adds the rising sign and houses.

Times in UTC: a birth late in the evening in the Americas, or early in the morning in Asia, can fall on the neighbouring UTC date.

December 2026: full moon December 24, 2026, Cancer · new moon December 9, 2026, Sagittarius.

Your decan: the third decan of Sagittarius

Each sign is divided into three 10° decans, and each decan has a sub-ruler that shades the sign's core. Degrees 20–30 of Sagittarius belong to Saturn: where you face limitation and, through facing it, build mastery. Read it as Sagittarius with a Saturn accent — the fire core is unchanged, the emphasis moves.

Decan tarot card · Golden Dawn attribution

Ten of Wands

Burden · Responsibility · Completion. The card assigned to this ten-degree slice of the zodiac — a birthday card in the same sense a sun sign is a birthday sign: one lens on the date, not a verdict.

Read the Ten of Wands in full on My Day Check →

All the tarot cards for December 18: decan, sign, ruling planet and year card →

What the date can't tell you

The Sun is one placement out of ten. Your Moon sign changes every two to three days, so Sagittarians born on December 18 in different years have different Moons; your rising sign changes every two hours and needs a birth time and place. Those two carry most of what people mean by "personality" in a chart.

Born December 18? Add your year, time and place

Your Moon and rising depend on the year and hour. Computed here in a few seconds — then your full chart with a preview of its reading, no sign-up.

Or browse the twelve possibilities: Sagittarius Sun with each Moon → · just my Moon sign · how the free birth chart calculator works

Classic matches for a December 18 birthday

By sun sign, Sagittarius pairs most easily with Aries, Leo, Libra, Aquarius. Sun-sign compatibility is the coarse layer; the couple reading compares both full charts.

Common questions

What zodiac sign is December 18?

December 18 is Sagittarius, the mutable fire sign ruled by Jupiter. The Sun sits at roughly 26° Sagittarius on this date, in the third decan.

What decan is December 18?

The third decan of Sagittarius (20°–30°), sub-ruled by Saturn. Decans divide each sign into three 10° slices; the sub-ruler adds a second flavour to the sign's core — here where you face limitation and, through facing it, build mastery.

What tarot card is December 18?

In the Golden Dawn system each decan has a minor arcana card: for the third decan of Sagittarius it is the Ten of Wands (burden, responsibility, completion). It's a birthday card in the same way a sun sign is — one lens, not a verdict.

What Moon sign is someone born on December 18?

It depends on the year, and in 47% of years on the hour too. For example: in 1980, Taurus; in 1990, Capricorn; in 2000, Virgo or Libra; in 2010, Taurus; in 2020, Aquarius. Over 1980–2030 the Moon on December 18 was most often in Libra. A birth time and place pin it down.

Does everyone born on December 18 have the same chart?

No. They share the Sun in Sagittarius, but the Moon changes sign every two to three days, the rising sign every two hours, and the outer planets by year. Two people born December 18 in different years can have almost nothing else in common in their charts.