Moon phase

Moon phase

Show the moon's age, phase, and illumination for a date, plus days to the next full and new moon.

Date

Calculated in this browser — the date never leaves the device.

Mean-lunation estimate for 1900–2100. The real orbit is elliptical, so the true phase can be up to about a day off — not for astronomy-critical use.

How to use

Pick a date.
Run the calculation.
Read the phase, age, and upcoming events.

What it supports

Mean-lunation estimate for 1900–2100; the real orbit is elliptical, so the answer can be up to about a day off. Not for astronomy-critical use.