The GP or so was talking about airplane mode though. I assume nothing gets through in that case. Personally I'd use DND rather than airplane mode.
Further, you can schedule it or even trigger by certain calendar events. Very convenient if you have small children and don't want the random calls from grandparents or old friends checking in at inconvenient times (apparently if they don't have children but working a lot they don't consider 9pm to be "a bad time" - how should they?).
We used Airplane mode at nights before (even before we had kids), but were stressed about missed emergencies from relatives and stopped doing that.
Disclaimer: I get approx. 2 calls per week, and this is mostly businesses calling back, etc. I still don't want to miss emergencies though.