Zodiac Sign Dates: The Twelve Signs, and How to Tell If You Were Born on a Cusp
Zodiac date tables in magazines look fixed, but if you were born on one of the boundary days you soon notice that different sources disagree. That is because the moment the Sun changes sign is different every year, sometimes by a whole day. The table below uses our engine to calculate every Sun ingress from 1950 to 2030 in Taipei local time, so cusp babies can look themselves up.
The twelve zodiac signs and their dates
| Sign | Usual dates (Taipei) | Actual start dates, 1950–2030 | Years starting on the usual date |
|---|---|---|---|
| Aries | Mar 21 – Apr 19 | Mar 20 to Mar 21 | 59.3% |
| Taurus | Apr 20 – May 20 | Apr 19 to Apr 21 | 84% |
| Gemini | May 21 – Jun 20 | May 20 to May 22 | 84% |
| Cancer | Jun 21 – Jul 22 | Jun 21 to Jun 22 | 63% |
| Leo | Jul 23 – Aug 22 | Jul 22 to Jul 24 | 76.5% |
| Virgo | Aug 23 – Sep 22 | Aug 22 to Aug 24 | 80.2% |
| Libra | Sep 23 – Oct 22 | Sep 22 to Sep 24 | 82.7% |
| Scorpio | Oct 23 – Nov 21 | Oct 23 to Oct 24 | 60.5% |
| Sagittarius | Nov 22 – Dec 21 | Nov 22 to Nov 23 | 70.4% |
| Capricorn | Dec 22 – Jan 19 | Dec 21 to Dec 23 | 81.5% |
| Aquarius | Jan 20 – Feb 18 | Jan 20 to Jan 21 | 71.6% |
| Pisces | Feb 19 – Mar 20 | Feb 18 to Feb 20 | 82.7% |
"Usual dates" uses the start date that occurred most often in 1950–2030; "actual start dates" is the earliest and latest start dates across those 81 years, in Taipei local time (including daylight saving time in 1945–1979). Ingress moments were found to the second by bisection.
Every sign's start date floats within two or three days. Taurus is the most stable, starting on Apr 20 in 84% of years; Aries is the least, starting on Mar 21 in only 59.3% of years. If your birthday falls inside a sign's "actual start dates" range, you need your birth year and time to be sure.
Note that these are Taipei dates. The ingress is the same instant worldwide, so in time zones behind Taiwan (Europe, the Americas) the local date can be a day earlier; the calculator below converts for any birthplace.
Born on a cusp? Check your Sun sign
Enter your birth date, birth time and birthplace to see exactly which sign and degree the Sun was in. A Sun at 29° or 0° means you were born on a cusp day; without a birth time, the calculator tells you whether the Sun changed sign that day. Everything is calculated in your browser; nothing is uploaded.
Tropical zodiac, Placidus houses, true node. Enter the local clock time on your birth certificate; daylight saving time is removed automatically from the birthplace's time-zone history, so there is no need to convert it yourself. If your town is not listed, pick the nearest large city.
Why the cusp dates move from year to year
The Sun takes 365.2422 days to go once around the zodiac, nearly six hours more than a calendar year. So each year the ingress happens about six hours later, and after four years the leap day of February 29 pulls it back. That is why a sign's start date wanders back and forth over two or three days.
The other reason is time zones. The Sun changes sign at the same instant everywhere, but the local date differs: an ingress at 3 p.m. in Taipei is still the early hours of the same day in New York, while an ingress at 7 a.m. in Taipei is the previous evening in New York. So a date table made for one country can be a day off in another.
How to tell your sign if you were born on a cusp
- Check the table first. If your birthday is outside the "actual start dates" range, there is nothing to worry about; the usual dates apply.
- If it is inside the range, you need the year and time. Enter your full birth date and time in the calculator above and see which sign and degree the Sun is in.
- If you don't know your birth time, the calculator compares the Sun's position at 00:00 and 23:59 on your birthday and, if it changed sign that day, lists both. Read both signs and see which sounds more like you.
People often say cusp babies have "a bit of both signs". At any given instant the Sun is in exactly one sign; but a Sun in the last or first few degrees of a sign is often read as carrying some color from the neighboring sign. That is astrological interpretation, not an astronomical gray zone.
The twelve signs at a glance: elements, modalities and rulers
| Sign | Element · modality | Ruler | In one line |
|---|---|---|---|
| Aries | Fire · Cardinal | Mars | Acts first and thinks on the way; loves being the one who starts things. Patience is the lifelong lesson. |
| Taurus | Earth · Fixed | Venus | Steady and grounded; wants results you can see and touch. Change needs time to be trusted. |
| Gemini | Air · Mutable | Mercury | Endlessly curious; learns the world by talking and trading ideas. Several threads at once is normal. |
| Cancer | Water · Cardinal | Moon | Led by feeling and family; fiercely protective of the people who matter. Security comes first. |
| Leo | Fire · Fixed | Sun | Needs a stage and needs to be seen; warm, generous, and proud of what it makes. |
| Virgo | Earth · Mutable | Mercury | Methodical and detail-minded; sees what is broken and wants to fix it. Harder on itself than on anyone else. |
| Libra | Air · Cardinal | Venus | Cares about fairness and harmony; sees every side, which is also why decisions come slowly. |
| Scorpio | Water · Fixed | Mars (modern: Pluto) | Intense and perceptive; trust is built slowly, but once committed it is all-in. |
| Sagittarius | Fire · Mutable | Jupiter | Drawn to distant places and bigger meaning; optimistic, blunt, and allergic to being tied down. |
| Capricorn | Earth · Cardinal | Saturn | Goal-driven and enduring; willing to put in the hard years for a long-term payoff. Takes responsibility seriously. |
| Aquarius | Air · Fixed | Saturn (modern: Uranus) | Prizes independence and freedom of thought; idealistic about groups and often a step ahead of them. |
| Pisces | Water · Mutable | Jupiter (modern: Neptune) | Deeply receptive and easily absorbs other people's moods; rich imagination, blurry boundaries. |
The element describes the kind of energy: Fire is passionate and active, Earth practical and steady, Air thinking and communicating, Water feeling. The modality describes the rhythm: the cardinal signs (Aries, Cancer, Libra, Capricorn) start things and begin exactly at the equinoxes and solstices; the fixed signs sustain; the mutable signs adapt. Modern astrology adds Pluto, Uranus and Neptune as rulers of Scorpio, Aquarius and Pisces.
Zodiac signs are not the constellations in the sky
Astrology's twelve signs divide the ecliptic into equal 30° segments starting from the vernal equinox; this is the tropical zodiac. It began aligned with the constellations of the same names, but over two thousand years the precession of the Earth's axis has moved the equinox point about 24° westward, so when the Sun enters Aries astrologically today, it is actually still among the stars of Pisces.
This is also where the "Ophiuchus" story comes from. The astronomical constellation boundaries were drawn by the International Astronomical Union in 1930, and the Sun really does pass through Ophiuchus every year. But astrology uses twelve equal seasonal divisions and never followed the constellation boundaries, so there is no thirteenth sign to worry about. Vedic astrology uses the sidereal zodiac, which stays aligned with the stars, so the same person's Sun sign often moves back one sign there.
A straight word: a birth chart is a language, not a prophecy
A birth chart draws the sky at the moment you were born so you can talk about personality and life themes in terms of planets, signs and houses. The planetary positions are astronomical fact and can be calculated very precisely; readings such as "Mars in Aries means drive" are astrological tradition, not scientific findings. It is a fine tool for knowing yourself and sorting out your thoughts, but it cannot make decisions for you. Everything on this site is for reference and entertainment only; for health, investment or legal matters, please consult a professional.
Cast your full birth chart
Enter your birth date, time and place to get your Sun, Moon, Ascendant, all ten planets, the twelve houses and the aspects in one go, with a reading for each placement. Everything is calculated in your browser.
Zodiac sign dates FAQ
Born on March 20 or 21: Pisces or Aries?
It depends on the year and time. Across 1950–2030, Aries began in Taipei on March 20 or 21, most often on Mar 21 (59.3% of years). Enter your full birth date and time in the calculator above to be sure.
Why do different websites give different zodiac dates?
Two reasons. First, the moment of the ingress changes each year, so a table can only give the most common date. Second, many tables are calculated for Greenwich or US time, which can be a day off elsewhere. This page is calculated for Taipei time, and the calculator works for any birthplace.
Is Ophiuchus a thirteenth zodiac sign?
Astronomically the Sun does pass through the constellation Ophiuchus every year, but astrology's twelve signs are equal divisions of the ecliptic starting from the vernal equinox and have nothing to do with the constellation boundaries, so astrology has no Ophiuchus sign.
How is your Sun sign determined?
By the Sun's position on the ecliptic at the moment of birth: 0°–30° is Aries, 30°–60° is Taurus, and so on, one sign every 30°. 0° is the vernal equinox, which is why Aries begins at the March equinox each year.
Do zodiac signs have anything to do with BaZi months?
Yes. Each BaZi month begins at a solar term that is exactly the Sun reaching 15° of a sign, so the BaZi Yin (Tiger) month always has the Sun in the second half of Aquarius or the first half of Pisces. See the table on the birth chart page.