Option Explicit
 
Private Sub Form_Load()
    Dim Startdatum As Date
    Dim Enddatum As Date
    Dim Zeitdifferenz As Long
 
    Startdatum = CDate("10.04.2013 12:45")
    Enddatum = CDate("12.04.2013 16:30")
 
    Zeitdifferenz = CLng(DateDiff("n", Startdatum, Enddatum))
    MsgBox CStr(Zeitdifferenz) & " Minuten"
End Sub