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...

Maarten · Answer

Thanks a lot I got to the part with the switch but it just was'nt very efficient your second method is very nice!

Alan · Answer

I was just playing around some more with this and I found that this simpler (though more cryptic) version also works: using System; class Program { static void Main() { DateTime dt = new DateTime(2007 12 17); int rest = RestOfWeek(dt); Console.WriteLine(rest); // 4 Console.ReadLine(); } static int RestOfWeek(DateTime dt) { int rest = 5 - (int)dt.DayOfWeek; if (rest == -1) rest = 5; return rest; } } The reason it works is because in the DayOfWeek enum Sunday has a a value of 0 Monday a value of 1 and so on up to 6 for Saturday.

Alan · Answer

This should work OK: using System; class Program { static void Main() { DateTime dt = new DateTime(2007 12 17); int rest = RestOfWeek(dt); Console.WriteLine(rest); // 4 Console.ReadLine(); } static int RestOfWeek(DateTime dt) { switch (dt.DayOfWeek) { case DayOfWeek.Saturday: case DayOfWeek.Sunday: return 5; case DayOfWeek.Monday: return 4; case DayOfWeek.Tuesday: return 3; case DayOfWeek.Wednesday: return 2; case DayOfWeek.Thursday: return 1; default: return 0; } } } Incidentally according to my calendar 12 April 2009 is a Sunday and 4 December 2009 is a Friday. So I've done the example on a date we can both agree was a Monday 17 December 2007 :)