Empty completed date on draft submissions export incorrect

Draft submissions have no completed date, but when you export these submissions, an incorrect value is shown.

It should show an empty cell in the data dump (using excel) but currently it's being evaluated by the date function, which fails, an returns Dec 31, 1969 date.

Previous issue, which I added as a parent, resolved evaluating the completed date to an actual date format.

My end users downloads draft submissions as well and error was found.

I attached a snapshot as an example.