The horoscope cuts the year into twelve equal signs, pinned to the March equinox: the day in spring when day and night are the same length, as the Sun crosses from the southern half of the sky into the northern. The Sun, meanwhile, crosses thirteen constellations of very unequal size. And Earth's slow wobble moves the equinox along the stars, about one day's worth every 70 years, so it has drifted a whole constellation since the signs were fixed. This is where the Sun really is on the dates the horoscope gives, in 2026.
The equinox, drifting
Why the signs have slipped a place
2026 ADToday · the equinox is in Pisces
The ✦ is the March equinox, where the Sun's path crosses the sky's equator. The signs are counted from it, so wherever it goes, they go. Earth's slow wobble has carried it back about 30 degrees since 131 BC, from the edge of Aries into Pisces, and each sign with it.
Ophiuchus 19 days · the thirteenth constellation; the horoscope calls these days Sagittarius
No sign
about 27 March
Cetus, grazed · Cetus, the Sea-Monster, is not on the Sun’s path, but around 27 March the ecliptic passes so close to its northern edge that the Sun’s disc overlaps it while the Sun’s centre stays in Pisces. A graze, not a visit.
Read your horoscope sign in the first column and the constellation in the last. For most dates it is the one before: the Sun is in Pisces for most of the sign Aries, in Aries for most of Taurus, and so on round the year. The sign was named for where the Sun was on those dates about 2,200 years ago. Earth’s axis has wobbled a twelfth of the way round since, which moves the whole calendar one constellation along.
Is Ophiuchus the 13th zodiac sign?
It is the thirteenth constellation on the Sun’s path, and always has been: the ecliptic ran through it long before the International Astronomical Union drew the modern boundaries in 1930. It is not a sign, because signs are equal twelfths of the year and have never followed the constellation boundaries. Nothing was added and nothing changed. If you were born in the first half of December, the Sun was in Ophiuchus, and the horoscope calls you a Sagittarius because it stopped looking at the sky some time ago.
Why do the day counts vary so much?
The constellations are irregular shapes drawn round the figures, not equal slices. Virgo is enormous and the Sun takes about six and a half weeks to cross it; the ecliptic clips only the northern claw of Scorpius, so the Sun is through in under a week. The signs ignore all of this by design, which is fine for a horoscope and less fine as a description of the sky.
The dates here are for 2026. They shift by about a day every seventy years, so they hold for anyone alive now, and the calculator checks the exact boundary for the day, and the hour, you were born.