A season that ends where the zodiac starts
The tropical zodiac is measured from the March equinox, the moment the Sun crosses the celestial equator going north. That instant is zero degrees of Aries by definition, which makes it the last instant of Pisces. The whole system is counted forward from there in thirty degree steps, so Pisces occupies 330 to 360 degrees and closes the circle.
The equinox generally falls on 20 March and, less often, on the 19th or 21st. It moves because the tropical year is roughly 365.2422 days rather than 365, so the event slides about six hours later through each common year and springs back when February gains a day. The opening boundary, where Aquarius hands over, has no such anchor and simply drifts with the same cycle around the nineteenth of February.
Length, and the orbit speeding down
Pisces takes a little under thirty days and a half. Earth passed perihelion, its closest point to the Sun, in early January, and by late February it has begun the long slowing towards aphelion in July. So the signs are lengthening again through this stretch: Pisces is slightly longer than Aquarius before it and slightly shorter than Aries after it.
None of this is visible in the usual list of star sign dates, which quotes a range to the nearest day and hides a two day spread between the longest and shortest signs. A table computed for a specific year shows the length outright.
Neptune, Jupiter and mutable water
Pisces is mutable water. Its traditional ruler is Jupiter, shared with Sagittarius, and modern practice reassigned it to Neptune after that planet's discovery in 1846, usually keeping Jupiter as co-ruler. The two readings differ: Jupiter gives the generous, expansive, meaning seeking side of the sign, while Neptune supplies the dissolving, boundaryless material that most contemporary descriptions lean on.
Being mutable and last, Pisces has the job of ending a season and the whole cycle with it. The month closes northern winter and runs directly into spring, which is a large part of why the sign is written about in terms of dissolution and release rather than of building anything.
Equinox births, and the same dates upside down
A birthday on 19 or 20 March is one of the most frequently misassigned in the zodiac, since the equinox can fall on either date and at any hour of the day. There is no cusp between Pisces and Aries: the Sun holds one longitude at each instant, so it is on one side of zero degrees Aries or the other. A birth time and the time zone in force at the birthplace on that date settle it, and nothing less will.
The times themselves are global. An ingress is one moment for the entire planet, so the range is identical in Wellington and in Oslo. Only the season reverses, with Pisces closing the southern summer and leading into autumn rather than spring. The tropical zodiac was defined by northern seasons and this is where that assumption is easiest to see.
Questions people ask about this
When does Pisces season end?
At the March equinox, the instant the Sun crosses the celestial equator northward, which is also the start of Aries and the origin of the whole tropical zodiac. It usually happens on 20 March, with the 19th and 21st both occurring in some years.
When does Pisces season start?
Around 18 or 19 February, when the Sun leaves Aquarius at 330 degrees of ecliptic longitude. No equinox or solstice marks that point, so the calendar date shifts through the leap year cycle. The table above computes it for the year you choose.
Is Pisces ruled by Neptune or Jupiter?
Jupiter is the classical ruler, held since long before the telescope. Neptune was discovered in 1846 and modern astrology gives it rulership of Pisces, typically retaining Jupiter as co-ruler. Most current writing about the sign draws far more on Neptune than on Jupiter.
Why is Pisces called the last sign?
Because the tropical zodiac is counted from the March equinox, and Pisces occupies the final thirty degrees before that point is reached again. The ordering is a consequence of where the measurement starts, not a ranking of the signs.
I was born on 20 March. Am I Pisces or Aries?
It depends on the hour and on the year. The equinox has fallen on the 19th, 20th and 21st in living memory and can occur at any time of day. Take the exact instant for your birth year, convert it to the clock that was in force where you were born, and compare.