I’m not sure if this is what you are looking for, but there used to be a Things Quiet Down feature in the old SmartThings app. Nowadays without it in the new SmartThings app, I use a Virtual Switch in a Smart Lighting Routine (disclaimer Smart Lighting isn’t available world-wide) that can be used as the trigger for SmartThings Routines (Automations).
Also, there are other options in the below thread that use WebCore.