Amount of Weekdays in a period

I need to find out how Weekdays there are between two days.

That means..... Mon, Tue, Wed, Thur, Fri...

how can i do this?
I know i can not just divide the Amount of days by 5 (for the weeks) and then subtract (2 * Amount of weeks)' (for the weekend), because the first date may start on a Thursday...

Can anybody help me.

1. Get a number of whole weeks between the two given dates, multiply by 5
2. Add the number of workdays in the starting week and in the ending one.

try this:

vb Code:

Sub CountDayOfWeekA(ByVal fromDate As Date, ByVal toDate As Date)
 
    Dim theCounter As New Dictionary(Of DayOfWeek, Integer)
    Dim d As Date = fromDate
 
    Dim ctr As Integer = 0
 
    Dim sb As New System.Text.StringBuilder
    sb.Append("Your start date was a " & fromDate.DayOfWeek.ToString & ".")
    sb.Append(ControlChars.CrLf & ControlChars.CrLf)
 
 
    Do While d <= toDate
        If theCounter.ContainsKey(d.DayOfWeek) Then
            theCounter(d.DayOfWeek) += 1
        Else
            theCounter.Add(d.DayOfWeek, 1)
        End If
        d = d.AddDays(1)
        ctr += 1
    Loop
 
    For Each entry As KeyValuePair(Of DayOfWeek, Integer) In theCounter
        sb.AppendFormat("{0} {1}s" & vbNewLine, entry.Value, entry.Key)
    Next
 
    sb.Append(ControlChars.CrLf)
    sb.Append("There are " & Format(ctr, "###,###,###,###,###") & " days between then and your end date.")
    sb.Append(ControlChars.CrLf & ControlChars.CrLf)
 
    Dim elapsedHours As Long = ((ctr - 2) * 24) + (24 - DateAndTime.DateDiff(DateInterval.Hour, CType("00:00:00", Date), CType(dtp1.Value.TimeOfDay.ToString, Date))) + DateAndTime.DateDiff(DateInterval.Hour, CType("00:00:00", Date), CType(dtp3.Value.TimeOfDay.ToString, Date))
 
    sb.Append("or " & Format(elapsedHours, "###,###,###,###,###") & " hours (approx.)")
    sb.Append(ControlChars.CrLf)
 
    Dim elapsedMinutes As Long = ((ctr - 2) * 1440) + (1440 - DateAndTime.DateDiff(DateInterval.Minute, CType("00:00:00", Date), CType(dtp1.Value.TimeOfDay.ToString, Date))) + DateAndTime.DateDiff(DateInterval.Minute, CType("00:00:00", Date), CType(dtp3.Value.TimeOfDay.ToString, Date))
 
    sb.Append("or " & Format(elapsedMinutes, "###,###,###,###,###") & " minutes (approx.)")
    sb.Append(ControlChars.CrLf)
 
    Dim elapsedSeconds As Long = ((ctr - 2) * 86400) + (86400 - DateAndTime.DateDiff(DateInterval.Second, CType("00:00:00", Date), CType(dtp1.Value.TimeOfDay.ToString, Date))) + DateAndTime.DateDiff(DateInterval.Second, CType("00:00:00", Date), CType(dtp3.Value.TimeOfDay.ToString, Date))
 
    sb.Append("or " & Format(elapsedSeconds, "###,###,###,###,###") & " seconds (approx.)")
    MessageBox.Show(sb.ToString, "Summary", MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1, MessageBoxOptions.DefaultDesktopOnly, False)
 
End Sub