diff --git a/src/AutoRest.CSharp/Common/Output/Builders/BuilderHelpers.cs b/src/AutoRest.CSharp/Common/Output/Builders/BuilderHelpers.cs
index bebf647746d..f00d68e7050 100644
--- a/src/AutoRest.CSharp/Common/Output/Builders/BuilderHelpers.cs
+++ b/src/AutoRest.CSharp/Common/Output/Builders/BuilderHelpers.cs
@@ -89,6 +89,11 @@ public static Constant ParseConstant(object? value, CSharpType type)
                 _ => SerializationFormat.Duration_ISO8601
             },
 
+            _ when schema.Type == AllSchemaTypes.Duration => SerializationFormat.Duration_ISO8601,
+            _ when schema.Type == AllSchemaTypes.DateTime => SerializationFormat.DateTime_ISO8601,
+            _ when schema.Type == AllSchemaTypes.Date => SerializationFormat.DateTime_ISO8601,
+            _ when schema.Type == AllSchemaTypes.Time => SerializationFormat.DateTime_ISO8601,
+
             _ => schema.Extensions?.Format switch
             {
                 XMsFormat.DateTime => SerializationFormat.DateTime_ISO8601,