Looping countdown

Hi everyone.
I’ve got this countdown timer
http://web.ukonline.co.uk/dooj/countdown.fla

What a need to do is make it countdown to the weekend, Friday night, which is easy enough.

What I can’t do is make the timer wait until midnight Sunday and start again, counting down to the next weekend.

Can anyone help me with this code, or better yet show me an FLA sitting on the net somewhere that does exactly what I need?
Thanks.