diff --git a/ReportImp/Wabe/Invoicing/CollectiveInvoiceCreation.cs b/ReportImp/Wabe/Invoicing/CollectiveInvoiceCreation.cs
index df8c230ec..3b85c2552 100644
--- a/ReportImp/Wabe/Invoicing/CollectiveInvoiceCreation.cs
+++ b/ReportImp/Wabe/Invoicing/CollectiveInvoiceCreation.cs
@@ -137,8 +137,9 @@ namespace Wabe.Invoicing
                 while (start <= ende)
                 {
                     DateTime monatStart = start; //new DateTime(start.Year, start.Month, 1);
-                    DateTime monatEnde = monatStart.AddMonths(1); //ende.AddDays(1); 
-                    if (ende.AddDays(2) < 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(1) < monatStart.AddMonths(1))
                     {
                         monatEnde = ende.AddDays(1);
                     }