Phase notes

Last Quarter

Three weeks in. Half lit again, the other half this time, with the moon a quarter of an orbit from finishing.

What you see

A half disc that rises around midnight and sits in the morning sky, which is why so many people never notice this one.

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 270 degrees of that angle, three quarters 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.