I like Time Announce during the day while I am working. But I want it off when I am sleeping.
Apple's Do Not Disturb function will mute notifications and sounds associated with them, but it has no effect on Time Announce.
Elsewhere on this site there is an old answer from a number of years ago that offered this script:
do shell script "defaults write ./com.apple.speech.synthesis.general.prefs TimeAnnouncementPrefs -dict TimeAnnouncementsEnabled -bool YES"
Similar script to turn it off.
Another answer can be found here, but goes back to the days of Mountain Lion:
I am new here and a rank beginner to Aapplescript. I do not have the privilege of commenting yet to seek clarification from the authors of the answers presented.
These scripts do not work on Mac OS X High Sierra (10.13). While the first script will compile, when run nothing happens. The script from the page referenced won't even compile. Syntax error about an unknown token after an identifer.
In addition, making a change manually to this preference in settings requires my password to unlock. Can AppleScript or Automator deal with that too?