How ZzzTimer Works

Sleep Cycles

ZzzTimer calculates optimal sleep times based on the average length of a human sleep cycle, which is approximately 90 minutes.

Calculating Bedtimes

When you input a wake-up time, ZzzTimer suggests bedtimes that allow you to complete full sleep cycles, helping you wake up feeling more refreshed.

Calculating Wake Times

If you input a bedtime, ZzzTimer suggests wake-up times that coincide with the end of a sleep cycle, potentially making it easier for you to wake up.