Set Business Hours
You can set the days and times when you want to be reachable on your phone number and optionally play a message outside office hours (or forward to an alternative number).
Log in to the app and go to settings, then choose the business hours schedule. (1)

Select the days and times when you want to be reachable.

Click save.
Go back to settings and, if desired, choose a closed message. (2). Done!