Schedule commands for later using 'at'

There have been a number of times when I've realized that I must restart some service at a production server. In such enviroments, restarting a critical service ( e.g. MySQL on a webserver ) in a production enviroment is simply a no-go during hours with traffic. And since the lowest possible traffic is during morning's early hours, you can either "schedule" your service restart to occur after going out with friends for a couple of beers, be awake {until|at} that time.... or simply let your server know that something needs to be done at that time.