diff --git a/Utilities/QueryBuilder.cs b/Utilities/QueryBuilder.cs
index 2196a0a3c3ed8d7650019deded113bd04622da88..a10e047ffed0c85fb5531b83b9a20ef597109c71 100644
--- a/Utilities/QueryBuilder.cs
+++ b/Utilities/QueryBuilder.cs
@@ -358,6 +358,10 @@ namespace Infrastructure.Utilities
 
 		public QueryBuilder Between(string fieldName, string datetime1, string datetime2)
 		{
+			if (datetime1.IsNullOrEmpty() || datetime2.IsNullOrEmpty())
+			{
+				return this;
+			}
 			_Where.Append(String.Format(" and ({0} >= '{1}' and {0} < '{2}')", fieldName, datetime1, datetime2));
 			return this;
 		}