Phase notes

Full Moon

The moon is opposite the sun, so the whole face we can see is lit. It is one instant rather than a night, and the day that holds it is what this site labels a full moon.

What you see

A complete disc, rising as the sun sets. When the alignment is exact the moon slides into our shadow and the night carries a lunar eclipse.

Next two years

The dates when the moon sits closest to the middle of this band.

The eight phases

Where the name comes from

A phase is only the angle between the sun and the moon as we see it. This one sits at 180 degrees of that angle, half of the way through a cycle that runs 29.53 days.

Crescent means less than half the disc is lit, gibbous means more than half, and the quarters are the two moments in between. The quarter names count orbit, not brightness - a first quarter moon looks like a half.

Every date of the year

Three hundred and sixty-six pages, one for each date, each with the phase for that day printed year by year.