Annoying! How to mute mac when display sleep?

[yalag]

I have a Mac pro and an external display, whenever I sleep my display for bed time the computer is not muted. All night, it just makes all kind of sounds from notifications.

How do I fix it?

 

[Small White Car]

Go in the System Preference and click "Notifications." Turn on the 'Do Not Disturb' check box that says "When the Display is Sleeping."

For good measure you could also set it to come on at 10 PM or so and then it'll silence it even if you've accidentally left the screen on.