Zodiac sign dates: the full list, and why the cusps move

The twelve zodiac signs and their usual dates are Aries (March 21 – April 19), Taurus (April 20 – May 20), Gemini (May 21 – June 20), Cancer (June 21 – July 22), Leo (July 23 – August 22), Virgo (August 23 – September 22), Libra (September 23 – October 22), Scorpio (October 23 – November 21), Sagittarius (November 22 – December 21), Capricorn (December 22 – January 19), Aquarius (January 20 – February 18), and Pisces (February 19 – March 20). The exact start of each sign shifts by up to two days from year to year, so if your birthday falls near a boundary, check the year.

The full list of zodiac signs and dates

Why do the dates change from year to year?

A sign does not begin on a calendar date. It begins at the precise moment the Sun reaches a particular point on the ecliptic: 0° Aries, 0° Taurus, and so on. Several things make that moment drift:

• The calendar year is not exactly as long as the solar year. A year of seasons is about 365.24 days. The Gregorian calendar keeps up by adding leap days, so sign changes slide later through a four-year cycle and jump back after each leap day.
• Time zones. The Sun enters Sagittarius at one instant worldwide. In 2026 that is November 22 at 2 a.m. US Central Time, which is still November 21 in Honolulu.
• Orbital speed. Earth moves faster in early January and slower in early July, so the signs are not exactly equal in duration on the calendar.

How much do the start dates actually vary?

We calculated every Sun sign change from 1950 to 2030 with Astronomy Engine, using Universal Time. Here is the range of calendar dates on which each sign began:

So if you were born on, say, October 23, you might be a Libra or a Scorpio depending on the year and your time zone. That is what people mean by being "born on the cusp."

The 2026 Sun sign changes

For reference, here is when the Sun changes signs in 2026, calculated with Astronomy Engine and rounded to the hour in US Central Time:

How to check your sign if you were born on a cusp

You need your birth date, birth time, and time zone or place. Then:

1. Open our sun sign calculator.
2. Enter your date and time.
3. It calculates the Sun's exact position at your birth and tells you which side of the line you fall on.

If you do not know your birth time and were born on the boundary day itself, you may not be able to know for certain. In that case, read both sign profiles and see which fits. Our guide to cusp signs explains how astrologers interpret births right on the edge.

Why tropical astrology ties signs to the seasons

Western astrology uses the tropical zodiac, which starts Aries at the March equinox, the moment the Sun crosses the celestial equator heading north. The other cardinal signs begin at the solstices and the September equinox. This keeps the signs locked to the seasons, which is why modalities follow the seasonal cycle.

Over centuries, a slow wobble in Earth's axis called precession has shifted the constellations relative to the equinoxes. That is why the sidereal zodiac, used in Vedic astrology, gives different dates. Neither system is "wrong"; they measure from different starting points. This site uses the tropical zodiac throughout.

What about Ophiuchus?

Every few years a headline announces a "13th sign," Ophiuchus. It is a real constellation that the Sun passes in front of in late November and early December. But the tropical signs are twelve equal 30-degree divisions of the ecliptic, not the constellations themselves, so Ophiuchus has no place in them. Your sign has not changed.

Common misconceptions about sign dates

"The dates are fixed by tradition." They are calculated each year from the Sun's actual position, which is why lists differ by a day.

"My sign changed when I moved time zones." Your sign is fixed at the moment and place of your birth. Moving later doesn't affect it.

"Born at midnight means the earlier sign." It depends on when the Sun crossed the boundary, which can happen at any hour.

How to double-check any sign date yourself

1. Note the birth date, time, and city.
2. Enter them in the sun sign calculator.
3. If the result surprises you, check the time zone: births before standard time zones or during daylight saving time are a common source of error.

The takeaway

The usual date list works for most birthdays. If yours falls within a day or two of a boundary, the year, time, and place of birth matter. Take thirty seconds with the calculator and you will know for sure.