Perhaps a data-completiontime attribute?

This is probably a refinement for later (or a useful practice exercise for the learner ? :- ), but I notice myself reaching occasionally for a completion time on status=completed items, if only in order to sort them in reports.

Yes, eventually want some way to track when an item is completed. Though the idea of tracking it like that in a separate, but linked/dependent, attribute doesn’t seem ideal. I need to think on this one a bit more.