What a star sign is based on
Your star sign (or Sun sign) is simply the segment of sky the Sun appeared to be passing through on the day you were born. Western astrology divides the Sun's yearly path into twelve equal segments of 30 degrees each, and gives each one a name, a symbol and a slice of the calendar. Because the Sun takes almost exactly a month to cross each segment, every sign owns roughly four weeks of birthdays, and the whole cycle starts again with Aries at the spring equinox in late March.
Whether any of this says something about your personality is a matter of tradition and taste rather than science, and this page makes no claims either way. What the calculator does is entirely factual: it takes a date and looks it up against the standard published ranges. Everything runs in your browser and the date is never sent anywhere.
The full list of star sign dates
- Aries ♈: 21 March to 19 April (fire)
- Taurus ♉: 20 April to 20 May (earth)
- Gemini ♊: 21 May to 20 June (air)
- Cancer ♋: 21 June to 22 July (water)
- Leo ♌: 23 July to 22 August (fire)
- Virgo ♍: 23 August to 22 September (earth)
- Libra ♎: 23 September to 22 October (air)
- Scorpio ♏: 23 October to 21 November (water)
- Sagittarius ♐: 22 November to 21 December (fire)
- Capricorn ♑: 22 December to 19 January (earth)
- Aquarius ♒: 20 January to 18 February (air)
- Pisces ♓: 19 February to 20 March (water)
These are the ranges you will see most often in print. Treat the first and last day of each range as approximate, for reasons covered below.
Worked examples
Cusps, and why the dates wobble
The Sun does not check a calendar before changing signs. It crosses each 30-degree boundary at a precise instant, and that instant drifts within a window of about a day across the four-year leap cycle, then snaps back when the leap day catches things up. It also lands at different local times around the world, so a baby born in London and one born in Sydney at the same moment can technically sit either side of a boundary. Printed horoscopes freeze all this into fixed dates, and different publishers freeze it slightly differently, which is why one magazine starts Aries on 20 March and another on 21 March.
If your birthday sits on one of the boundary dates, you are a cusp baby: your true side of the line depends on your birth year and time of birth, and enthusiasts would look it up in an astronomical table. For everyone else, the standard ranges above give the same answer every time. Either way it is a fun bit of calendar trivia to know, along with which day of the week you were born on, which our day of the week finder can tell you, and exactly how many days old you are, which is a job for the age calculator.
Frequently asked questions
I was born on a cusp, which sign am I?
A cusp is a birthday on or next to the boundary between two signs, such as 19 or 20 April. The Sun crosses each boundary at a precise moment that varies by a day or so from year to year, so people born on a boundary date can genuinely fall either side depending on their birth year and time. This calculator uses the most widely published fixed dates, which are right for the vast majority of birthdays.
Why do some sites give slightly different dates for each sign?
Because the real boundary moves. The moment the Sun passes from one sign to the next shifts within a roughly one-day window across the four-year leap cycle, and it also depends on time zone. Different publishers freeze that moving target on slightly different calendar dates, which is why you will see Aries start on 20 or 21 March depending on where you look.
What are the 12 star signs in order?
Starting from the spring equinox they run Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. The cycle then starts again with Aries in late March.
Is my star sign the same as the constellation the Sun was actually in?
Usually not. Western astrology uses the tropical zodiac, which is fixed to the seasons, but the Earth's slow wobble (precession) means the constellations have drifted by about one sign over the last two thousand years. Astronomers also point out the Sun passes through a thirteenth constellation, Ophiuchus. None of this changes your star sign, which is a calendar tradition rather than an astronomical measurement.
Is my date of birth stored anywhere?
No. The lookup happens entirely in your browser and nothing is sent to any server. Refreshing the page clears the date.