Turn on Airplane Mode When You're Asleep
The primary function of airplane mode is based on a superstition – that preventing a phone from trying to emit or receive radio waves will avert some sort of freak communication glitch, and convince a perfectly good aircraft to go into a tailspin. The mode's real value is in preserving battery life, since a phone that isn't searching for data or cell reception is using significantly less energy. So unless you need to be reachable at all hours of the night, when you're sleeping at home, pretend you're 30,000 feet in the air, and activate airplane mode. The phone will still work as a clock (and alarm), but won't be pointlessly leaking power.