This app was mentioned in 11 comments, with an average of 2.36 upvotes
I highly recommend Nights Keeper. It is a do not disturb app that I have found very useful. Does what it says, and has a better (i think) whitelist capability than other, similar apps (like Agent's do not disturb function, for one).
Linkme: Nights Keeper
Swipe down from the top on the home screen. Hit the four squares in the top right to expand the drawer. There should be a star icon that changes from Priority" mode to "Always Interrupt". Then change the Interruptions setting in the Sound settings. The only problem I had with this was that due to a bug, my phone would still buzz once the battery reached 100% charging overnight and it would wake me. Nights Keeper was the solution for me. https://play.google.com/store/apps/details?id=com.nightskeeper&hl=en
Nights Keeper is the only thing I've found to do what you want and also not have it vibrate when it reaches 100% battery level while charging overnight. https://play.google.com/store/apps/details?id=com.nightskeeper
The only way I have found to make it work and also not have the phone vibrate in the middle of the night once it is fully charged is with Nights Keeper. https://play.google.com/store/apps/details?id=com.nightskeeper&hl=en
You use a widget to toggle on Priority mode that actually silences everything, but let's the alarm through.
nights keeper is great for this, it's the one i use, very simple but does the job
https://play.google.com/store/apps/details?id=com.nightskeeper&hl=en
I used Nights Keeper
https://play.google.com/store/apps/details?id=com.nightskeeper
I use Nights Keeper so only certain people can wake me up at night.
https://play.google.com/store/apps/details?id=com.nightskeeper