Countdown clock function

I need a function on a website that can count down each day during fixed hours. In example. Company has opening hours from 08:00 - 16:00 So at 08:00 the countdown starts counting down the amount of hours there is from 08:00 - 16:00: 08:59:59 (hours left, minutes left, seconds left) When it reaches 16:00 it should post a statement like: Sorry. The office is closed for today. You can send us an email or call again tomorrow at 08:00 There are a lot of scripts out there that can be used far along the way, and im open for suggestions as to what to use. I have a few ideas myself, that we could disguss. A lot of other work can come your way, if the cooperation is good.