I presume that you are in bed between those times? If so, whilst I appreciate that the Airplane mode will save some power, why wouldn't you just plug the phone in while you sleep?
Just wondering

 

If it's plugged in and charged everyday who gives a toss lol

 

But the Wildfire has a Lithium Ion battery.

 

But.... if you're asleep you're most likely near a plug so any battery life savings are irrelevant - what most people want is a method to extend battery life during the day (when they need it to work as a phone).

 

Or just switch it off. Why bother with Airplane mode at night when you're sleeping??

 

Just do the same, but schedule it to do that at the times you know the office is likely to want to contact you