Your sign is set by which 30° section of the ecliptic the Sun was in on the day you were born
The Western zodiac splits the ecliptic, the path the Sun follows over a year, into twelve 30° sections starting at the March equinox. The Sun in 0° to 30° means Aries, 30° to 60° means Taurus, and so on. The moment the Sun crosses into the next section shifts by a few hours every year, so the fixed tables you often see, such as "March 21 to April 19", can give the wrong answer for people born on a boundary day.
The calculator above works out the Sun's position (its longitude) for the day you were born. If your birthday is a boundary day, it shows both signs and the time of the changeover, and entering your birth time narrows it to one. The Chinese zodiac animal is also based on the moment of Lichun rather than January 1.
How to use the calculator
- Enter your date of birth: your sign and animal appear at once. The date is calculated on this screen only and is not kept anywhere.
- Check the time zone: choose the time zone of the place you were born. The default is US Eastern (New York), so change it if you were born elsewhere.
- On a boundary day, add the time: if the result shows two signs and the changeover time, enter your birth time to settle on one.
- Read the wheel and the table: the Sun marker on the wheel points to its position on your birthday, and the table beside it lists when each sign began that year.
Boundary dates that change from year to year
These are the start dates of each sign in US Eastern time (New York). The same sign can start a day earlier or later depending on the year.
| Sign | 1990 | 2000 | 2010 | 2024 | 2026 |
|---|---|---|---|---|---|
| Aries | 3/20 | 3/20 | 3/20 | 3/19 | 3/20 |
| Taurus | 4/20 | 4/19 | 4/20 | 4/19 | 4/19 |
| Gemini | 5/21 | 5/20 | 5/20 | 5/20 | 5/20 |
| Cancer | 6/21 | 6/20 | 6/21 | 6/20 | 6/21 |
| Leo | 7/22 | 7/22 | 7/22 | 7/22 | 7/22 |
| Virgo | 8/23 | 8/22 | 8/23 | 8/22 | 8/22 |
| Libra | 9/23 | 9/22 | 9/22 | 9/22 | 9/22 |
| Scorpio | 10/23 | 10/22 | 10/23 | 10/22 | 10/23 |
| Sagittarius | 11/22 | 11/21 | 11/22 | 11/21 | 11/22 |
| Capricorn | 12/21 | 12/21 | 12/21 | 12/21 | 12/21 |
| Aquarius | 1/20 | 1/20 | 1/19 | 1/20 | 1/19 |
| Pisces | 2/18 | 2/19 | 2/18 | 2/18 | 2/18 |
For example, in 2024 Taurus began in New York on April 19 at 09:57. Someone born on the afternoon of April 19 is a Taurus, yet a fixed table that runs Aries through April 19 would say Aries. For a birthday close to a boundary, the time of birth is what settles it.
Why your birthplace's time zone matters
The Sun crosses into the next sign at one instant for the whole world, but the date and clock time of that instant differ by time zone. In 2024 Aries began on March 19 at 23:04 in New York and on March 20 at 04:04 in Madrid. In 2026 it began on March 20 at 10:37 in New York and at 15:37 in Madrid. So two people born on the same calendar date can have different signs depending on where they were born. The calculator also takes past daylight saving time and changes in standard time into account.
When does the Chinese zodiac animal change?
The Chinese zodiac (East Asian zodiac) runs through Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog and Pig in a 12-year cycle. Two rules are used for the day the animal changes.
- Lunar New Year rule: the animal changes on the first day of the lunar calendar. Lunar New Year falls on a new moon between January 21 and February 20, so the date differs every year.
- Lichun rule: the animal changes at Lichun (Start of Spring, solar longitude 315°). This is the rule used in Bazi (Four Pillars) astrology, and it falls around February 3 to 5 each year. As this calculator computes it in US Eastern time, Lichun was on February 4 at 03:21 in 2024 and on February 3 at 14:55 in 2026.
The calculator sets the animal from the moment of Lichun, and for births between January 21 and February 20, when the Lunar New Year rule could differ, it also gives the second animal. If you were born on or before January 20, you belong to the previous year's animal under either rule. For example, someone born on January 10, 1990 is a Snake, not a Horse (the animal of 1990).
Elements, modalities and ruling planets
| Element | Signs |
|---|---|
| Fire | Aries · Leo · Sagittarius |
| Earth | Taurus · Virgo · Capricorn |
| Air | Gemini · Libra · Aquarius |
| Water | Cancer · Scorpio · Pisces |
Modalities split the signs into cardinal signs that begin a season (Aries, Cancer, Libra, Capricorn), fixed signs in the middle (Taurus, Leo, Scorpio, Aquarius) and mutable signs that lead out of it (Gemini, Virgo, Sagittarius, Pisces). Ruling planets follow classical astrology (Aries and Scorpio Mars, Taurus and Libra Venus, Gemini and Virgo Mercury, Cancer the Moon, Leo the Sun, Sagittarius and Pisces Jupiter, Capricorn and Aquarius Saturn). All of these are traditional astrological groupings. The old tool's personality-score bars had no basis, so they are not included here.
The zodiac and science
NASA explains that astrology is not the same as astronomy and that its claims are not based on scientific evidence. The constellations of astronomy are 88 regions set by the International Astronomical Union (IAU) in 1922, with boundaries approved in 1928. Their sizes vary widely, so they do not match the astrological signs, which divide the ecliptic into exact 30° sections. Enjoy your sign as conversation and fun, and do not use it to judge people or to make important decisions.
Common mistakes
- Judging a boundary day by a fixed table: for birthdays that straddle a boundary, such as April 19 to 20 or June 20 to 21, the answer can differ from year to year.
- Using the time zone where you live now: what counts is the time zone of the place you were born.
- Reading a January birthday by the calendar year: for births on or before January 20, the animal is the previous year's.
- Entering a lunar birthday: this calculator takes a solar (Gregorian) birthday. If you only know your lunar birthday, convert it first.
Limits and cautions
- The Sun's position comes from a low-precision astronomical formula, so changeover times carry an error of about ±15 minutes. Compared with the U.S. Naval Observatory (USNO) equinox and solstice times for 2024, the difference was 2 to 7 minutes.
- You can enter birthdays from 1900 to 2100. There is no Lunar New Year table, so check a calendar for the Lunar New Year rule.
- It does not calculate Bazi, compatibility or horoscopes.
Date checked The sources were checked on 2026-10-09, and the boundary times were calculated with the formula above.
Sources
- 01IAU: The Constellations88 constellations in 1922, boundaries approved in 1928
- 02NASA Space Place: Star FinderAstrology differs from astronomy and its claims are not based on scientific evidence
- 03U.S. Naval Observatory: Earth's SeasonsEquinox and solstice times (used to compare calculation accuracy)
Frequently asked questions
Why do zodiac dates differ by a day from site to site?
Your sign depends on which 30° section of the ecliptic the Sun is in, and the moment the Sun crosses into the next section shifts by a few hours every year. In US Eastern time, Aries began on March 19 in 2024 but on March 20 in 2026. Sites that use a fixed date table may place people born on a boundary day in the wrong sign.
What if I was born on a boundary day?
Enter your birth time and the result narrows to one sign. In New York, the Sun moved from Pisces to Aries on March 19, 2024 at 23:04, so someone born earlier that day is a Pisces and someone born after it is an Aries. If you do not know the time, the calculator shows both signs.
Why do I choose the time zone of my birthplace?
The Sun crosses into a new sign at the same instant everywhere, but the local date and time differ by time zone. On March 21, 1995, the Sun entered Aries at 03:16 in Madrid, so that day is a boundary day there. In New York the same instant was 21:16 on March 20, so all of March 21 is Aries. Past daylight saving time and changes in standard time are also taken into account.
Does the Chinese zodiac animal change on January 1?
No. The animal normally changes at Lunar New Year or at Lichun. This calculator uses the moment of Lichun (solar longitude 315°) and gives a separate note for births between January 21 and February 20, when the Lunar New Year rule could differ. Anyone born on or before January 20 has the previous year's animal under either rule.
When is Lichun?
Lichun (Start of Spring) falls around February 3 to 5 each year. As this calculator computes it in US Eastern time, it was on February 4, 2024 at 03:21 and on February 3, 2026 at 14:55. If you were born on Lichun itself, you need to enter the time of birth for a single animal.
What are the elements and ruling planets?
They are ways of grouping the 12 signs in Western astrological tradition. The elements are fire (Aries, Leo, Sagittarius), earth (Taurus, Virgo, Capricorn), air (Gemini, Libra, Aquarius) and water (Cancer, Scorpio, Pisces), and the modalities are cardinal, fixed and mutable. Ruling planets follow classical astrology (for example Mars for Aries and Venus for Taurus).
Can your sign tell you about your personality?
There is no scientific evidence for that. NASA explains that astrology is not the same as astronomy and that its claims are not based on scientific evidence. This calculator finds your sign and animal as part of culture and does not show personality scores.
Are these the same as the constellations in astronomy?
No. The International Astronomical Union (IAU) divides the whole sky into 88 constellation regions of very different sizes. The astrological signs are exact 30° sections of the ecliptic measured from the March equinox, so they do not match the real constellation regions.