determine rest of week with DateTime

Question

I have a DateTime object wich contains the current date, now I want C# to determine how long the week will last (mon - fri). I've been trying several things, but nothing seems to work.
For example, if the current date would be 12/04/2009, and it would be a monday, it should return 4 (there are four days left to friday, friday included).

Sorry for any spelling mistakes, I normally speak duch...