diff --git a/Data-Design.md b/Data-Design.md
index 0878de1..c61466a 100644
--- a/Data-Design.md
+++ b/Data-Design.md
@@ -21,8 +21,8 @@ Design for the data in recklist
 
 - String: todo: used to hold the actual todo item
 - Boolean: done: is done
-- Date: due_by: due date
-- Date: completed_on: date it was checked off
+- u64: due_by: utc due date
+- u64: completed_on: utc date it was checked off
 - Vector: todos: sublist of todos
 
 ## Saving