Aries dates20 March to 20 April, starting at the March equinox

Astronomers and astrologers are describing one event here. The March equinox is the moment the Sun, moving north along the ecliptic, crosses the equator projected onto the sky. Its ecliptic longitude at that moment is 0°, and 0° of longitude is, by definition, 0° Aries. So the start of Aries is not near the equinox or tied to it by custom. It is the equinox, to the second.

That definition is old. Ptolemy says in the Tetrabiblos (I.10) that a circle has no natural beginning, so the sign which begins with the spring equinox, Aries, is taken as the starting point of them all. In I.22 he goes further and argues that the signs must be counted from the equinoxes and solstices, because their natures come from those starting places and no others. Western astrology has measured the zodiac that way ever since, so an almanac's equinox time and an astrologer's Aries time always match.

The instant is fixed; the date is not. Over the 80 years from 1951 to 2030, the equinox landed on 20 March in US Eastern time in 69 years, on 21 March in 8, and on 19 March in 3. The 21 March years were 1951, 1955, 1959, 1963, 1967, 1971, 1975 and 1979: every one of them the year before a leap year, and none after 1979. The 19 March years are 2020, 2024 and 2028, all leap years. In US Pacific time the equinox has fallen on 19 March in every leap year from 2000 onwards (2000, 2004, 2008, 2012, 2016, 2020, 2024 and 2028), and on 21 March for the last time in 1963.

Why so many tables still say 21 March

Because they were right once. A zodiac table drawn up in Britain in the 1950s or 1960s would have seen Aries begin on 21 March in a good share of years: in London time that happened 15 times between 1951 and 1979, and only 7 times from 1980 to 2030, the last in 2007. Copied from magazine to website, the date outlived the sky.

The slide comes from the calendar. A plain four-year leap cycle adds a day slightly too often, so between century corrections each equinox drifts earlier by most of a day per hundred years. The years 1700, 1800 and 1900 dropped their leap days and pulled the date back. The year 2000 kept its 29 February under the 400-year rule, so no correction has happened in living memory, and the next one is not due until 2100. Until then the March equinox keeps creeping towards the 19th, one leap year at a time.

Two smaller corrections. Day and night are not quite equal on the equinox: refraction lifts the Sun into view early and sunrise is timed from the top of the disc, so at mid-northern latitudes the day wins by several minutes. Ptolemy's "equal nights and days" (I.11) is near enough for naming a sign. And in Sydney the March equinox opens autumn, not spring. An Australian born on 25 March is still an Aries; the tropical zodiac is defined by the equinox point, which is the same instant for the whole planet.

The first four columns are the March equinox in each zone, which is also the moment Aries began. The last two are the moment it ended and Taurus began. Born between your year's two times, you have the Sun in Aries.

Every birthday from 22 March to 18 April is Aries in all 80 years and all four zones below. Both ends of the sign need a closer look, because the handover day contains both signs:

A New York birth on 20 March is the hardest case. In 69 of the 80 years the Sun changed sign at some point that day, so the answer turns on the clock: in 2027, for instance, the equinox fell at 4:25 pm Eastern, and a baby born that morning has a Pisces Sun while one born that evening is an Aries. In 2024 the equinox came at 11:06 pm on 19 March Eastern, so a 20 March 2024 birth anywhere in the eastern US was Aries from the first minute. The zodiac sign calculator works this out from the date, time and place, and the March zodiac signs page covers every day of the month.

The April end splits almost evenly. Taurus began on 20 April in 41 of the 80 years and on 19 April in 39, but the recent decade leans hard to the 19th (8 of the 10 years 2021 to 2030). Anyone born on 19 or 20 April should check the year table or the zodiac sign calculator before settling the question, and the April zodiac signs page has the Taurus side. There is no blended sign at either end: a Sun at 29° Pisces has not changed yet, and one at 0° Aries has.

Two slow planets have just reached the equinox point together. Neptune first entered Aries on 30 March 2025, slipped back into Pisces on 22 October 2025, and came back for good on 26 January 2026. It stays until 22 May 2038, with one last retrograde dip into Pisces after that. Neptune takes about 165 years to go round, so the last people born with it in Aries were born in the 1860s and early 1870s.

Saturn arrived alongside. Its first visit ran from 25 May 2025 to 1 September 2025, after Aries season had finished, and the long stay runs from 14 February 2026 to 13 April 2028. So an Aries baby born in 2026 or 2027, or between 20 March and 13 April 2028, has the Sun, Saturn and Neptune all in Aries. Three planets in one sign is a cluster worth reading by house, as the stellium guide describes. The traditional reading adds a twist: Aries is Saturn's fall, the sign where Ptolemy (I.19) puts its "depression", opposite its exaltation in Libra. Saturn and Neptune last met in 1989, in Capricorn; their conjunction in the opening degrees of Aries in 2026 starts a new cycle of roughly 36 years.

Older Aries readers have their own rows in the table, such as Uranus in Aries for every Aries born from 2011 to 2018. For adults the practical question is when Neptune crosses their own Sun degree. It moves a little over 2° a year, with retrograde loops that cross most degrees three times:

Aries splits into three 10° slices, each with a typical date range (in UTC; it slides a day with the year, like the sign):

The face column is where the whole Chaldean sequence of faces begins. Mars takes the first ten degrees of the zodiac, then the Sun, then Venus, and the order of the seven planets carries on round the other 33 decans from there. So the first decan of Aries is the one slice of the year that is Mars's sign and Mars's face at once. The modern triplicity column gives Aries, Leo and Sagittarius instead, ruled by Mars, the Sun and Jupiter.

No, but it is below the middle. The Shymea rarity study matched 62,187,026 US births from 2000 to 2014 to the exact ingress times and found 5,062,002 Aries, 8.14% of the total and eighth of the twelve signs. An even split would give each sign 8.33%.

Astronomy alone would put Aries higher. The Sun spends 30.46 days in Aries, a mid-length stay, which in 2014 would have produced 8.34% of births. The real figure that year was 8.08%, a ratio of 0.969: only Capricorn fell further short of its Sun time. Fewer babies are born in the Aries weeks than the clock predicts. The other registries in the study put Aries in much the same place: it ranked eighth in Canada in 2024 (8.20%), eighth in Australia in 2023 (8.27%), eighth in New York City in 2024 and seventh in England and Wales in 2025 (8.27%).

April, mostly. Aries starts on about 20 March and runs to about 19 or 20 April, so 37% of the sign falls in March and 63% in April.

The stars tell a different story, and it does not affect the sign. Using the International Astronomical Union's constellation borders, the Sun was in front of the stars of Pisces from 12 March 2026 and did not reach the constellation Aries until about 03:00 UTC on 19 April, less than a day before the sign Aries ended. For almost the whole of tropical Aries in 2026, the Sun stood among the stars of Pisces. That gap is precession, the slow turning of the equinox point against the stars, and Ptolemy's argument in I.22 is why Western astrology stays with the equinox. Sidereal astrology, used mainly in India, follows the stars and starts Aries in mid-April; it is a separate system, not a correction.

The equinox falls on 20 March 2027 at 20:25 UTC, which is 4:25 pm Eastern and 1:25 pm Pacific on 20 March, 8:25 pm in London, and 7:25 am on 21 March in Sydney. Aries ends when the Sun enters Taurus on 20 April at 07:18 UTC. The New Moon in Aries comes on 6 April at 16°57′, the Sun degree of people born around 6 April.

The slow planets matter more. Neptune turns retrograde on 9 July at 6°40′ Aries and direct on 15 December at 3°51′, so from July to December it sits on the Sun of people born from about 24 to 27 March. Saturn turns retrograde on 9 August at 27°53′ and direct on 24 December (UTC) at 21°01′, which puts it across the Sun of people born from about 11 to 18 April for the last five months of the year. The Aries 2027 horoscope has the year month by month, and the Aries horoscope the current week.

Libra and Aries are opposite signs and opposite equinoxes: the one where the days start winning and the one where the nights do, with Venus's diplomacy facing Mars's directness across the table. Libra's own page is Libra dates and the September equinox. Leo and Sagittarius complete the fire triangle and sit a trine away, so Aries and Leo and Aries and Sagittarius are the easy pairings in the textbook sense. The square to Cancer that Ptolemy built into Mars's rulership is the classic friction pairing, the person who acts first beside the person who feels first; Aries and Cancer goes through it. Sun-sign matching is a blunt tool next to two whole charts compared in synastry.

The neighbours each have their own page: Pisces dates and the 20 March cusp and Taurus from 19 or 20 April. All twelve are on the zodiac signs by date hub.