What sleep researchers mean by a zeitgeber

Sleep researchers sometimes use the word zeitgeber. It means a time cue, or something that helps your body clock stay aligned with the day.

Light is one of the strongest zeitgebers. Morning brightness tells your body it is daytime. Evening darkness tells it the day is winding down. Food, movement and social routines can act as time cues too.

A sunrise alarm is useful because it turns morning light into a repeatable cue. The light happens at the same point in your routine, even when it is dark outside or the curtains are still closed.

You do not need to remember the word to use the idea. Give your body clearer morning cues and fewer mixed signals at night.