What was the moon
doing on your birthday?

Enter any date and get the exact phase, how much of the disc was lit, and the sign the moon stood in. Everything here is computed from astronomical algorithms — no lookup tables, no rounding to the nearest full moon.

Any date, past or future

Next new and full moons

New Moon · August 12The moon is between us and the sun, lit on the side we cannot see.17:36 UTC Full Moon · August 28Earth sits between sun and moon; the whole visible face is lit.04:18 UTC New Moon · September 11The moon is between us and the sun, lit on the side we cannot see.03:27 UTC Full Moon · September 26Earth sits between sun and moon; the whole visible face is lit.16:48 UTC

The eight phases

A full cycle takes 29 days, 12 hours and 44 minutes — the synodic month. These are the eight named stages, what the sky actually looks like in each, and what people have traditionally done with them.

New Moon0%Waxing Crescent1–49%First Quarter50%Waxing Gibbous51–99%Full Moon100%Waning Gibbous99–51%Last Quarter50%Waning Crescent49–1%

Phase compatibility

Two birthdays, two moons. See both phases side by side and what the pairing is traditionally read as — the version people share, with the astronomy kept honest.

Compare two dates →

Moon sign calculator

The moon changes sign every two and a half days, which is why your moon sign is rarely your sun sign. Enter a birth date to see where it stood.

Find your moon sign →

A phase is arithmetic; what it meant in your chart is not. If that is the question you actually came with, a personal reading is the short way to an answer. See a reading built from your birth moon →

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Why the dates here differ from your calendar app

Phase moments are instants, not days: a full moon at 04:18 UTC on the 28th is already the 27th in Los Angeles. Every time on this site is UTC, and stated as such, so you can convert deliberately instead of wondering which day is right.