Any countdown timer for posts?

Is there a countdown timer for posts? What I mean is, a timer that I could put in a sidebar or in the header that would say something like:
— Time until next post: 7 hours and six minutes.
— Next post will appear in 7 hours and six minutes.

Something like that, that would pick up the info from my scheduled posts so I didn’t have to do a lot of configuration stuff.

If such a thing doesn’t exist — and a cursory search didn’t reveal one right off the bat — then it sure should.