An electronic device displays a first user interface for specifying a sleep schedule and receives a first user input specifying a first time value for a start time or end time of a first scheduled sleep period. In response to detecting the first input, the electronic device displays a first visual indication with a first display property at a first value, if the duration of the first scheduled sleep period is below a preset threshold duration. The electronic device displays the first visual indication with the first display property at a second value, if the duration of the first scheduled sleep period is at or above the preset threshold duration.