Conditional Formattiing for Custom Date/Time

Hello Excel Gurus!

I am hoping that one of you can help me with an issue that I am having with Conditional Formatting in Excel 2007.

I have a custom date/time that I use ("ddd mm/dd/yy hh:mm "AM/PM") and would like to have it auto format to red text when hh:mm >= 4:00 PM. Additionally, I would like to have it auto format to red text when ddd= Sat or Sun, regardless of time (but not Mon-Fri, unless >= 4:00 PM). I'm thinking that this will require two seperate formulas, but I've not had any success yet.

I would appreciate any help you have to offer!

Thanks!
Shannon

So... I tried your formula, @etaf. Unfortunately, I couldn't seem to get it to work. It did format some cells, but not the right ones. I can't seem to understand why, either. I'm not an expert by any means on the excel-verse, but the basic logic seemed pretty good. Do you have any recommendations as far as what other options I might have?

Thanks!
Shannon