How about an iPhone mute function with a timer feature?

Here's an idea for an iPhone feature I'd love to see: a mute feature with a timer. Let me explain. I'm going to a meeting, church service, etc., so I set my iPhone's volume to vibrate only. After all, you don't want to get a phone call when the boss is on a tear or the preacher's really into his lesson.

iPhone Timer.jpg

However, if you're like me, you often forget to turn the volume back on afterwards. When I'm working, or relaxing at home, my iPhone may be charging or somewhere out of reach. I often find that I've missed several calls simply because I didn't hear the smartphone ringing. 

A mute function with a timer would be useful. Say, for example, the ability to have it on vibrate only for two hours. How about it, Apple?