At least on Android (I’d assume iOS does it as well), you can set Do Not Disturb (DND) to turn on and off automatically, based on the time. You can also designate certain contacts to be allowed to bypass DND, so the phone will ring normally. I setup DND a long time ago, because I don’t want to be bothered by random shit while I am trying to sleep. However, my job is such that I might reasonably be called at 03:00 and need to roll my arse out of bed and start working. So, the number they call from is set to bypass DND. My elderly mother and brother are both similarly set to bypass. It all works out quite well and if some random marketer figures out my number and calls in the middle of the night, I don’t get woken up to talk about my car’s warranty.