How To Get Week Number Of The Year

Once upon a time i need to create project using week number of the year. means i need to have a number which shows me week number. so below is how to get that result.

note :
i wrote something like (xxxxx - 1) that is because my project has a different week start date, so if i did not (-1) i'll have incorrect number. please remember the correct number based on world datetime is without (-1), that is my case my personal case....

code : Val(CAL.GetWeekOfYear(TanggalBerapa, CWR, DOW)) - 1












Imports System.Globalization

 Public Sub CHECKING_WEEK()

        Dim CI As New CultureInfo("en-IN")
        Dim CAL As Calendar = CI.Calendar

        Dim CWR As CalendarWeekRule = CI.DateTimeFormat.CalendarWeekRule
        Dim DOW As DayOfWeek = CI.DateTimeFormat.FirstDayOfWeek

        Dim Tgl As String = DtpDATE.Value.Day
        Dim Bln As String = DtpDATE.Value.Month
        Dim Thn As String = DtpDATE.Value.Year

        Dim TanggalBerapa As String = Thn & "-" & Bln & "-" & Tgl

        CAL.GetWeekOfYear(DateTime.Now, CWR, DOW)
        MsgBox("Tanggal " & Tgl & "-" & Bln & "-" & Thn & _
               " Adalah Minggu Ke-" & _
               Val(CAL.GetWeekOfYear(TanggalBerapa, CWR, DOW)) - 1 _
               & " Di Tahun " & Year(Now) & "")
    End Sub