diff --git a/Service/Plugins/SupportConceptValidator.cs b/Service/Plugins/SupportConceptValidator.cs
index a2fe72359..4b5dcc55d 100644
--- a/Service/Plugins/SupportConceptValidator.cs
+++ b/Service/Plugins/SupportConceptValidator.cs
@@ -27,17 +27,57 @@ namespace BeWo.Service.Plugins
 
 			bool isNew = !supportConcept.SupportConceptOid.HasValue;
 
+            // 1. Prüfe Datumsbereiche. Startdatum darf nicht größer als Enddatum sein
+            bool containsDatumCheck = false;
+            if (supportConcept.CostBearerRelations != null)
+            {
+                foreach (var c2s in supportConcept.CostBearerRelations)
+                {
+                    if (!containsDatumCheck)
+                    {
+                        var val = CheckDate(c2s.StartDate, c2s.EndDate);
+                        if (val != null)
+                        {
+                            result.Add(val);
+                            containsDatumCheck = true;
+                        }
 
-			// 1. Prüfe Datumsbereiche. Startdatum darf nicht größer als Enddatum sein
-
-			//ValidationResultDC resultDc = new ValidationResultDC();
-			//resultDc.Message = "Alles doof! Darfst nicht speichern!";
-			//resultDc.AllowSave = true;
-   //         result.Add(resultDc);
+                        if (c2s.ApprovalPeriodList != null)
+                        {
+                            foreach (var ap in c2s.ApprovalPeriodList)
+                            {
+                                if (!containsDatumCheck)
+                                {
+                                    val = CheckDate(ap.StartDate, ap.EndDate);
+                                    if (val != null)
+                                    {
+                                        result.Add(val);
+                                        containsDatumCheck = true;
+                                    }
+                                }
+                            }
 
+                        }
+                    }
+                    
+                }
+            }
+            
             return result;
 		}
 
+        private ValidationResultDC CheckDate(DateTime? start, DateTime? end)
+        {
+            if (start.HasValue && end.HasValue && start > end)
+            {
+                ValidationResultDC resultDc = new ValidationResultDC();
+                resultDc.Message = "Das Startdatum darf nicht größer als das Enddatum sein.";
+                resultDc.AllowSave = false;
+                return resultDc;
+            }
+            return null;
+        }
+
 		public virtual List<ValidationResultDC> ValidateSupportConceptDeletion(long supportConceptOid)
 		{
 			var result = new List<ValidationResultDC>();