HTC One Remix - Manual (Page 260)

Do not disturb mode
Use Do not disturb mode to reject calls, and silence audible alerts and
notifications, but still want to have a data connection available.
1. Go to Settings, and then tap Sound.
2. Tap the Do not disturb On/Off switch to turn it on and off.
3. Tap Do not disturb to set when you want Do not disturb to turn off,
or to allow the Clock app alarm and timer sounds to play when Do
not disturb is on.
The Do not disturb icon will appear in the notifications area of the status
bar. Even when Do not disturb mode is on, you'll still see notification icons
in the status bar to alert you of missed calls, new messages, calendar
events, alarms, and other notifications.
Allowing incoming calls to bypass Do not disturb mode
Add important contacts to an exceptions list so that you can still receive
their calls even when Do not disturb mode is on.
1. Go to Settings, and then tap Sound.
2. Tap Do not disturb.
3. Tap Do not disturb exceptions and then tap .
4. Choose whether to select contacts or groups to add to the
exceptions list.
5. Select the checkbox to allow incoming calls from contacts on the
exceptions list.
260 Settings and security