May 21 Zodiac Sign
Tradition: Western astrology. A tradition, not a forecast. Astrologers read it this way; the evidence does not.
By Suraj Giri
May 21 is Gemini on the dates most calendars use, but it is a boundary day: from 1950 to 2029, about 84 percent of May 21 birth hours in US Eastern time fell in Gemini and about 16 percent in Taurus.
You were born on a boundary day. The exact changeover shifts by up to a day depending on the year and the time of birth, so both signs are shown.
| Sign | Share | The Sun's degrees |
|---|---|---|
| Gemini | 84 percent | 0.0 to 1.6 degrees of Gemini |
| Taurus | 16 percent | 29.3 to 30.0 degrees of Taurus |
The Sun's move into Gemini landed between May 20 and May 21 (US Eastern time) in those years; the tropical year is about 365.24 days, so the moment shifts by hours from year to year and moves back after each leap day.
May 21 zodiac compatibility
If you are a Gemini
By this site's zodiac points method, a May 21 Gemini scores highest with Libra and Aquarius, a strong match at 8 of 8 points, then Aries and Leo, a good match at 5 of 8.
| Pair | Verdict | Points | Aspect |
|---|---|---|---|
| Gemini and Libra | strong match | 8 of 8 | trine |
| Gemini and Aquarius | strong match | 8 of 8 | trine |
| Aries and Gemini | good match | 5 of 8 | sextile |
| Gemini and Leo | good match | 5 of 8 | sextile |
If you are a Taurus
By this site's zodiac points method, a May 21 Taurus scores highest with Virgo and Capricorn, a strong match at 8 of 8 points, then Cancer and Pisces, a good match at 5 of 8.
| Pair | Verdict | Points | Aspect |
|---|---|---|---|
| Taurus and Virgo | strong match | 8 of 8 | trine |
| Taurus and Capricorn | strong match | 8 of 8 | trine |
| Taurus and Cancer | good match | 5 of 8 | sextile |
| Taurus and Pisces | good match | 5 of 8 | sextile |
Have your partner's birthday? Compare May 21 with your partner's birthday.
Scores come from this site's zodiac points method (formula 1.1), reviewed by Jahben R., astrologer, on 2026-09-23. How it works is on the methodology page.
Gemini at a glance for a May 21 birthday
If you are a Gemini
- Element: air
- Modality: mutable
- Ruler: Mercury
- Position: day 1 of 31 of Gemini
- Next sign: Cancer, from June 21
If you are a Taurus
- Element: earth
- Modality: fixed
- Ruler: Venus
- Position: the day after Taurus' last day on most calendars (May 20)
- Next sign: Gemini, from May 21
May 21 decan (Tradition)
In the triplicity system of decans, a tradition, May 21 falls at the end of the third decan of Taurus (20 to 30 degrees), ruled by Saturn, or the start of the first decan of Gemini (0 to 10 degrees), ruled by Mercury, depending on the year and hour.
The older Chaldean system of decans assigns different rulers.
Famous people born on May 21
- Andrei Sakharov, physicist, born 1921
- Mary Robinson, politician, born 1944
- Mario Mandžukić, football coach, born 1986
- Günter Blobel, biologist, born 1936
- Masato Morishige, footballer, born 1987
Birth dates from Wikidata (CC0), fetched 2026-09-26.
A note on May 21 birthdays
The cusp on May 21 favors Gemini by 84 percent to Taurus' 16, with the shift into Gemini already timed to this date. Astrologers read Mercury, Gemini's ruler, as governing talk and ideas, a contrast with Venus, the planet tradition assigns to Taurus and to affection shown through comfort. By this site's points method, Gemini forms its strongest matches with Libra and Aquarius at 8 points each, and good matches with Aries and Leo at 5 each.
Questions people ask
Is May 21 a Gemini or a Taurus?
Is May 21 on the Gemini and Taurus cusp?
Who is a May 21 Gemini or Taurus most compatible with?
Does the birth year change the zodiac sign for May 21?
Birthdays around May 21
- May 20, Taurus or Gemini
- May 22, Gemini
- All May birthdays
Sources
- astronomy-engine 2.1.19: the Sun's position; the methodology page records its check against NASA JPL Horizons, and the build checks it against published equinox and solstice times
- This site's zodiac points method: formula 1.1
- Wikidata (CC0): birth dates, fetched 2026-09-26