diff --git a/ReportImp/DomizielAnsbach/Invoicing/InvoiceHelper.cs b/ReportImp/DomizielAnsbach/Invoicing/InvoiceHelper.cs
index bcfa5e070..b2c66e0e2 100644
--- a/ReportImp/DomizielAnsbach/Invoicing/InvoiceHelper.cs
+++ b/ReportImp/DomizielAnsbach/Invoicing/InvoiceHelper.cs
@@ -39,7 +39,8 @@ namespace DomizielAnsbach.Invoicing
             while (start <= ende)
             {
                 DateTime monatStart = start; //new DateTime(start.Year, start.Month, 1);
-                DateTime monatEnde = new DateTime(start.Year, start.AddMonths(1).Month, 1); //ende.AddDays(1); // monatStart.AddMonths(1);
+                DateTime monatEnde = monatStart.AddMonths(1); //new DateTime(start.Year, start.AddMonths(1).Month, 1); //ende.AddDays(1); 
+                monatEnde = new DateTime(monatEnde.Year, monatEnde.Month, 1);
                 if (ende.AddDays(2) < monatStart.AddMonths(1))
                 {
                     monatEnde = ende.AddDays(1);