Settings & keep-time · Quiet Hours, pausing and schedules
How do I undo a change I just made in Quiet Hours?
Short answer: Click Revert to saved at the bottom of Settings → Quiet Hours to reload the last saved values. Changes save automatically, so if one has already saved, set it back by hand.
Click Revert to saved at the bottom of Settings → Quiet Hours. It reloads the last saved values into the page.
Because changes save automatically, use it promptly — once a change has been saved, simply set the value back by hand. If a value can't be saved, a warning appears in the same spot explaining why.