How to count week days without the weekend using VB.Net?

Question

So I have a date range. dateFrom and dateTo. I want to count how many days from dateFrom and dateTo without weekend. Example : user select Thursday's date until next week Monday's date. So it should be only 3 days instead of 5 days. Next if user select Saturday's date to Sunday's date it'll be zero. Any ideas on how to do it? Thanks !

Edit : I have a way on to count the days but it's included the weekends date. So how to count it excludes the weekends ?

  Private Function CalculateDaysBetweenDates() As Integer
        Dim dateFrom As DateTime = Convert.ToDateTime(datepickerFrom.Date)
        Dim dateTo As DateTime = Convert.ToDateTime(datepickerto.Date)
        Dim ts As TimeSpan = dateTo.Subtract(dateFrom)
        If Convert.ToInt32(ts.Days) > 0 Then
            radHalfday.Enabled = False
            radHalfday.Value = False
        Else
            radHalfday.Enabled = True
        End If
        Return 1
    End Function

*please, help me...

Answer 1

There is an edge case, same date, in this.

Private Function DaysBetween(dtFrom As Date, dtTo As Date) As Integer
    Dim rv As Integer = 0
    Dim dL As Date = If(dtFrom.Date <= dtTo.Date, dtFrom.Date, dtTo.Date)
    Dim dH As Date = If(dtFrom.Date <= dtTo.Date, dtTo.Date, dtFrom.Date)

    If dL <> dH Then 'dates different?
        rv = CInt((dH - dL).TotalDays) + 1 'incl. from and to

        While dL <= dH
            If dL.DayOfWeek = DayOfWeek.Saturday Then
                rv -= 1
            ElseIf dL.DayOfWeek = DayOfWeek.Sunday Then
                rv -= 1
                dL = dL.AddDays(5)
            End If
            dL = dL.AddDays(1)
        End While

    ElseIf dL.DayOfWeek >= DayOfWeek.Monday AndAlso dL.DayOfWeek <= DayOfWeek.Friday Then
        'same date
        'return 1 or 0(default) ??????????????????
        ' rv = 1
    End If
    Return rv
End Function