diff --git a/BMA.EHR.Domain/Extensions/DateTimeExtension.cs b/BMA.EHR.Domain/Extensions/DateTimeExtension.cs
index 6c536239..18f03079 100644
--- a/BMA.EHR.Domain/Extensions/DateTimeExtension.cs
+++ b/BMA.EHR.Domain/Extensions/DateTimeExtension.cs
@@ -14,7 +14,7 @@ namespace BMA.EHR.Domain.Extensions
 
         public static int DiffDay(this DateTime startDate, DateTime endDate)
         {
-            if (endDate < startDate)
+            if (endDate.Date < startDate.Date)
             {
                 throw new ArgumentException("End Date must greater than start date.");
             }