[Brian]

Abe - happy to help, and welcome aboard! If you switch to the "All Items" perspective, your completed actions will be visible. You can use the search field to locate and select the action you completed, then look at the "completed" field of the inspector.

If you're going to want to see this information on a regular basis, you may want to save a Perspective (a set of saved window settings) that helps you find the actions in question.

Do the following menu selections produce a view that would help you?

View -> Context Mode
View -> Sidebar Filter -> All Contexts
View -> Grouping -> Completed
View -> Sorting -> Completed
View -> Availability Filter -> Completed
View -> Status Filter -> Any Status

This approach will show all your actions grouped and sorted by when they were checked off. If this view does show what you're looking for, you can save it for further use by selecting
Perspectives -> Save window as -> New Perspective.

Now you can bring that view up from the Perspectives menu at any time.

If that view doesn't do what you want, there may be another combination of settings that does. Let us know what you need done differently and we're happy to help.