Thema: Ermittlung des ersten Tages einer Kalenderwoche nach DIN 1355

StandardModule: Modul1

Private Function DINWeek(dat As Date) As Integer
   Dim dValue As Double
   dValue = DateSerial(Year(dat + (8 - WeekDay(dat)) Mod 7 - 3), 1, 1)
   DINWeek = (dat - dValue - 3 + (WeekDay(dValue) + 1) Mod 7) \ 7 + 1
End Function

Function DINDay(iYear As Integer, iDIN As Integer)
   Dim iDay As Integer, iWeek As Integer
   If iYear = 0 Then
      DINDay = 0
      Exit Function
   End If
   iDay = 1
   iWeek = DINWeek(DateSerial(iYear, 1, 1))
   If iWeek <> 1 Then
      Do Until DINWeek(DateSerial(iYear, 1, iDay)) = 1
         iDay = iDay + 1
      Loop
   Else
      Do Until DINWeek(DateSerial(iYear, 1, iDay)) <> 1
         iDay = iDay - 1
      Loop
      iDay = iDay + 1
   End If
   DINDay = DateSerial(iYear, 1, iDay) + (iDIN - 1) * 7
End Function

Beiträge aus dem Excel-Forum zu den Themen UDF und DatumUndZeit