Where date request, acknowledge, and completed of copy-/layout-editing were stored?

I am working with two version of OJS, OJS 2.6 and OJS 3.1.
I need to display the dates of copy-editing and layoutediting process on the article page. I found the event_log table in OJS 2, but I think that’s not the correct table.

Which table(s) in the database does store the metadata?

Thank you…