March 21 Zodiac Sign: Pisces or Aries?

March 21 is a cusp birthday: in 12 of the 87 years from 1940 to 2026 the Sun entered Aries during March 21 (US Eastern Time), so people born that day are Pisces before the change time and Aries after it; in 75 years the change came earlier and the whole day was Aries. Your sign depends on the year and time of birth — see the table. Pacific Time: change during the day in 6 years, whole day Aries in 81, whole day Pisces in 0.

March 21 at a glance

• Possible Sun signs: Pisces up to the change, Aries from it on
• Elements: Pisces, Water; Aries, Fire
• Modalities: Pisces, Mutable; Aries, Cardinal
• Rulers: Pisces, Neptune (Jupiter in traditional astrology); Aries, Mars
• Data: NASA JPL Horizons, 1940–2030

Find your birth year and read across to the column for the zone you were born in. Where a time is printed, births earlier than that minute were Pisces and births at that minute or later were Aries; where the cell is blank, March 21 was Aries around the clock. One instant can sit on two calendar dates, and 1946 is the row to look at: its Eastern cell reads 00:33 EST while its Pacific cell stays blank, because when New York clocks showed 00:33 on March 21, Los Angeles clocks still showed 21:33 on March 20. The table covers the two coasts only; for Central, Mountain or any other zone, the answer comes from the birth chart. The March zodiac signs page sets this date among the other days of March.

Across 1940–2030, in US Eastern and Pacific Time alike, a change on this date never comes late in the day. Eastern times run from 00:22 EST in 1979 to 08:03 EWT in 1943, and Pacific times from 00:20 PST in 1963 to 05:03 PWT in 1943. The first two rows with a time, 1942 and 1943, are printed in War Time: EWT in the Eastern column for both years and PWT in the Pacific column for 1943. That wartime clock, one hour ahead, ran from February 9, 1942 to September 30, 1945. The computed rows for 2027 to 2030 show no time, and in no year of the 1940–2030 table does Pisces keep March 21 whole, Eastern or Pacific.

The local time of birth decides whenever your row prints a time, and it can decide for a birth outside Eastern and Pacific Time too. Give the free birth chart three details, the birth date, the hour and the birthplace, to check your Sun sign with your birth time; signing up is not required. Without a time, Astrolivo calculates the chart for 12:00 noon and marks the result as a noon chart.

Instead of relying on a single noon position, the calculator checks for any sign changes across your entire local birth date. If the Sun, the Moon, or another planet changes sign during that local day, the result shows each possible sign for that day rather than guessing a single one.

The planet themes below belong to Pisces and Aries as signs, and no March 21 birth is bound by them: astrology is an interpretive tradition, not a scientifically validated method.

A birth before the change minute has its Sun in Pisces. In astrology the search for universal truths is a Neptune theme, and Neptune is the modern ruler of Pisces; adventures belong to Jupiter, the sign's classical ruler. More on the sign is on the Pisces zodiac sign page.

A birth at the change minute or later has the Sun in Aries, and for Aries the classical and modern lists agree on one ruler, Mars. Discipline and stamina are the Mars themes astrology carries over to the sign. Aries gets its full treatment on the Aries zodiac sign page.

FAQ

Why do people call March 21 a cusp birthday? The Sun can leave Pisces for Aries on this date, and "cusp" is the popular tag for birthdays like that, not an extra sign. The Sun stands in one sign at any given moment, so a March 21 birth is Pisces or Aries, never both; in a year with a printed time, the minute of birth picks the side.

What time does the Sun move into Aries on March 21? That depends on the year. In the birth years 1940–2026 when the change fell on March 21 in Eastern Time, it came between 00:22 EST (1979) and 08:03 EWT (1943); the Pacific times run from 00:20 PST (1963) to 05:03 PWT (1943). In every other year from 1940 to 2030, in both time zones, the Sun had entered Aries on an earlier date, so all of March 21 was Aries.

How this page was made

Every time in the year table goes back to a NASA JPL Horizons calculation of the Sun's entry into Aries, 1940–2030; the IANA time zone database supplies the Eastern and Pacific clock readings. Sign elements, modalities and rulers follow the Wikipedia articles "Astrological sign," "Astrology and the classical elements" and "Planets in astrology," and the note on astrology's status follows "Astrology and science." Astrolivo's editorial team matched every statement to those sources while preparing the page; sign readings are the tradition's own.