diff --git a/src/main/resources/csharp/api.mustache b/src/main/resources/csharp/api.mustache
index 36053337bf5..0267c3633bd 100644
--- a/src/main/resources/csharp/api.mustache
+++ b/src/main/resources/csharp/api.mustache
@@ -48,8 +48,11 @@
         }
         {{/requiredParamCount}}
 
-        {{#queryParams}}if ({{paramName}} != null)
-          queryParams.Add("{{paramName}}", {{paramName}});
+		string paramStr = null;
+        {{#queryParams}}if ({{paramName}} != null){
+          paramStr = ({{paramName}} != null && {{paramName}} is DateTime) ? ((DateTime)(object){{paramName}}).ToString("u") : Convert.ToString({{paramName}});
+          queryParams.Add("{{paramName}}", paramStr);
+		}
         {{/queryParams}}
 
         {{#headerParams}}headerParams.Add("{{paramName}}", {{paramName}});