Using a outlet timer to charger my phone, good idea or no?

So I'm going to be buying a couple outlet timers for various things and I was wondering if this would be a good idea.

My iPhone charges in about an hour so I could set the timer to stop charging it after an hour as I sleep at night, it would then kick back on the 30 minutes before I wake up to ensure it's fully charged without having to 'charge it' all night.

I'm wondering if this would be at all helpful for using less electricity or for helping my battery life, or is it just a waste of time and a solution to a problem that doesn't exist?

Thanks guys.