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Moon phase calendar
The moon phase and illumination for every night of a month, plus the next full and new moon, for planning moonlit scenes or a dark-sky shoot.
All tools- Phase
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- Illumination
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- Age
- —Days since the new moon, in a 29.53-day cycle
- Next new moon
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- Next full moon
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Next new and full moon dates are approximate, within about a day, and in UTC.
How it works
The method behind the numbers.
The moon takes a mean 29.530588853 days to go from one new moon to the next (the synodic month). The tool counts that cycle forward from the mean new moon of 6 January 2000 at 14:20 UTC, then corrects each new and full moon, following Jean Meeus, Astronomical Algorithms.
phase = 0 at new moon, 0.5 at full, linear between the two
lit = (1 − cos(2π × phase)) ÷ 2- The real moon speeds up and slows down along its orbit, so the true phase can be off the mean by up to about 15 hours. The next new and full moon times add the main correction terms from the same chapter, which brings them within a few minutes of published tables. The phase name, age and lit share are measured from those corrected times; the quarters are placed halfway between, which can be a few hours out.
- A date stands for noon UTC. In North America that is the morning, so the phase in the evening of the same date is a few per cent further along.
- Moonrise and moonset depend on your place and need a full lunar position model, so they are left out rather than guessed. Check them for your location before a night shoot.
- For night skies, a thin crescent or a new moon keeps the sky dark. A full moon lights a landscape but washes out faint stars and the Milky Way.
- The drawing shows the moon as seen from the northern hemisphere. Pick the southern hemisphere to flip it the way it appears there.