need dayofweek count from date

for e.g.: for 08/19/2007, result is 3 (because it is 3rd sunday in august 2007 month).

for 08/28/2007, result is 4 (because it is 4th Tuesday in august 2007 month).

is there any .NET date functions? or need to write my own code.

found answer thanks. Return (oDate.Day - 1) / 7 +1.