1. Find "Do Not Disturb"
Tap Settings.
Tap Do Not Disturb.
2. Turn on Do Not Disturb
To set your phone to silent mode immediately:
Tap the indicator next to "Manual" until the function is turned on.
To set your phone to silent mode for specified periods of time:
Tap the indicator next to "Scheduled" until the function is turned on.
Tap the field below "Scheduled".
Tap From or To.
Drag hours and minutes upwards or downwards to specify the period of time in which you don't want to be disturbed.
Tap Do Not Disturb.
3. Select contacts
You can select which contacts can call you or send you messages even though Do Not Disturb is turned on.
You need to add the contact to your favourites before you can select Favorites.
You can create groups in iCloud on your computer.
Tap Allow Calls From.
Tap Everyone, No One, Favorites or the required group.
Tap Do Not Disturb.
4. Turn Repeated Calls on or off
You can set your phone to ring if the same person calls you twice within three minutes even though Do Not Disturb is turned on.
Tap the indicator next to "Repeated Calls" to turn the function on or off.
5. Select silent mode setting
You can set your phone to silent mode permanently or only when the screen lock is turned on. If the screen lock is turned off, you'll hear all calls and notifications.
Tap Always or Only while iPhone is locked.
6. Return to the home screen
Tap the Home key to return to the home screen.