After Do Not Disturb mode is enabled, the watch does not vibrate to remind you when it receives incoming calls, text messages, and other alerts.
Slide down on the watch face and tap the Do Not Disturb icon to select Do Not Disturb mode.
Enable Do Not Disturb: The watch immediately enters Do Not Disturb mode.
Scheduled DND and Auto turn on can be setted on the watch setting>Preferences>Do Not Disturb.
Scheduled DND: You can set the start time and end time of DND mode.
Smart DND: After you fall asleep wearing the watch, the watch automatically enters and exits DND mode.