[RESOLVED] DateDiff not working properly

[tgf-47]

I need to calculate the number of weeks between 2 dates. This will be used in a billing system.

If something comes in on Thursday, they must get billed for that whole week.

Here is my code that I tried. The code gives me wrong values. Only on the 3rd week, my week count is 1.

Private Function DIFF(ByVal THEDATE As Date)
        Dim i As Integer
        i = DateDiff("ww", THEDATE, Now.Date, FirstDayOfWeek.Monday)
        Return i
    End Function

Honestly I cant see why this isn't working properly. Probably my lack of experience. Can anyone help me here?

The code must be able to calculate the number of weeks between
12/15/2008 - 30/10/2010 for example