Why Aries gets to go first
Of the twelve zodiac signs, Aries is always listed first. That is because the signs are counted from the March equinox: 0° of the sun’s path is the point it reaches at that equinox, and Aries is the sign that begins there, running 0°–30°. The March equinox, when day and night are close to equal length and the Northern Hemisphere moves into spring, was also where several old calendars began the year.
The tropical zodiac (the system used throughout this site, and explained in full in tropical and sidereal zodiacs) is built directly on that starting point: 0° Aries is defined as the moment of the March equinox itself, and every other sign boundary is measured forward from it in even 30° steps.
Spring as the start of the year
Starting the year in spring has a long history. The Babylonian year began with the month of Nisannu, around the spring equinox, and the Persian new year, Nowruz, is still kept at the equinox itself. Traces of the convention persist in the Western calendar long after its new year moved to 1 January: September, October, November and December mean “seventh,” “eighth,” “ninth,” and “tenth” month, which only makes sense if the year they’re counting from began in March.
Rome’s own calendar tells the same story
The clearest illustration comes from Rome’s own calendar history. The earliest Roman calendar, traditionally attributed to Romulus, is said to have counted only ten months, beginning in March — which is exactly why the later months September through December carry number-based names that no longer match their position. January and February were added later, traditionally credited to the king Numa Pompilius, extending the year to twelve months but still, for a long stretch of Roman history, starting it in March. The start of the Roman civil year eventually moved to 1 January — a change usually dated to the mid-2nd century BCE, tied to when incoming consuls began taking office on that date — well before Julius Caesar’s calendar reform, in force from 45 BCE, standardised the length of months and years into something close to the structure still used today. Caesar’s calendar kept the January start, and by then the month names had been fixed for centuries, which is why they never caught up.
That did not settle the matter for Europe. Many places later began their year on other dates, and returned to 1 January only gradually: Venice in 1522, France in 1564, Scotland in 1600. England’s legal year began on 25 March, Lady Day, until the Calendar (New Style) Act 1750 moved it to 1 January from 1752. Until then an English date between 1 January and 24 March belonged, legally, to the year before.
Why this matters for the zodiac specifically
The zodiac is measured from the March equinox, not from 1 January, and that is the only sense in which Aries comes “first”. Aries occupying the first position isn’t a statement about Aries being astrologically superior to the other signs in any traditional sense — it’s simply where the count of the 360° cycle starts.
Why the equinox itself isn’t a fixed date
The March equinox is not a fixed calendar date. Because the year of the seasons doesn’t divide evenly into whole days — the same mismatch that requires leap years in the first place — it drifts about six hours later each year and jumps back most of a day at each leap year. This site’s own figures show the pattern: 2023’s equinox fell at 21:24 UTC on 20 March, 2024’s at 03:06, 2025’s at 09:01 and 2026’s at 14:46, all on 20 March. In UTC it fell on 20 or 21 March in every year from 1920 to 2026, and on 20 March in every year since 2008; across 1900 to 2100 as a whole the range is 19 to 21 March, with 19 March arriving from 2044. The full mechanism, which moves every other sign boundary in the same way, is covered in why zodiac dates shift from year to year.
The takeaway
The zodiac and several old calendars share one starting point, the March equinox, which is why Aries comes first. The convention is old enough to have left fossils in the modern calendar’s own month names, even though the civil new year moved to 1 January long ago — and in England not until 1752.