Calendar calculation reference
Exact Zodiac Sign Change Data: 2026–2028
A simple reference for the exact moments the Sun enters each tropical zodiac sign, plus the method behind the year-specific calendar pages.
Calculated and reviewed: August 31, 2026
What this data answers
Generic zodiac tables say things such as “Aquarius begins January 20.” That is good enough for most birthdays. The exact transition, however, happens at a particular moment. This dataset records that moment in UTC for each sign change from 2026 through 2028.
Four seasonal anchor points
| Year | Aries begins | Cancer begins | Libra begins | Capricorn begins |
|---|---|---|---|---|
| 2026 | Mar 20, 14:46 UTC | Jun 21, 08:25 UTC | Sep 23, 00:05 UTC | Dec 21, 20:50 UTC |
| 2027 | Mar 20, 20:25 UTC | Jun 21, 14:11 UTC | Sep 23, 06:02 UTC | Dec 22, 02:42 UTC |
| 2028 | Mar 20, 02:17 UTC | Jun 20, 20:02 UTC | Sep 22, 11:45 UTC | Dec 21, 08:20 UTC |
The four rows above are useful landmarks: in the tropical zodiac they line up with the March equinox, June solstice, September equinox and December solstice reference points.
How the calculation works
- Use the tropical ecliptic longitude of the Sun.
- Find the instant it reaches each 30-degree boundary: 0°, 30°, 60° … 330°.
- Record that instant in UTC.
- Round the published time to the nearest minute so the table is readable.
The astronomical position calculations were made with the Swiss Ephemeris software library using its Moshier calculation mode. Swiss Ephemeris also documents its higher-precision JPL-based ephemeris options; for these Sun-ingress tables, the published result is rounded to the nearest minute. The calculations here use only the Sun's tropical longitude; they do not depend on astrological personality interpretations.
What this data does not mean
It does not mean every place on Earth changes calendar date at the same moment. UTC is a common reference clock. Your local time can be hours earlier or later, so the local civil date can differ.
It also does not apply to sidereal-zodiac boundaries or official constellation boundaries. Those are different systems.
Version
Version 1.0 — August 31, 2026. The file is updated only if the calculation method, source data or included years change materially.
Sources
- Swiss Ephemeris documentation — calculation system
- NASA — Plane of the Ecliptic — plain astronomical background