Dawn is the light before sunrise — the twilight that begins when the sun is 18° below the horizon and ends as its edge appears.

The order runs astronomical, nautical, civil, then sunrise, each named for what it lets you do — see the faintest stars, take a sight, read a page. At mid-latitudes the whole passage takes about an hour and a half; at the equator, barely more than an hour, because the sun climbs straight up.

Its first stage is faint and starlit; its last, civil dawn, is bright enough to read by.