A full moon is the moment the moon stands opposite the sun, its whole face lit; it rises at sunset and is up all night.

Sol takes the instant of opposition from the lunar ephemeris and shows it in your own clock; a full moon at three in the morning belongs to the night before. It rises within minutes of sunset because it stands opposite the sun, and its light is some four hundred thousand times fainter than the sun's — still enough to cast a shadow and to wash out the Milky Way.

Full to the minute only once, though it looks full for a night either side; Sol names each one and lists the year's.