Bug: Timestamp not generated properly when marking book as "Finished"

Description of your request or bug report: I went to a book page and marked a book as finished; that book was not in my library at any point in time before then. When I went to my dashboard, I saw this:

That “8 hours ago” really needs to match the other two updates time-wise.

(I’ve noticed this several places on the site, where for some reason sometimes 00:00:00 is the preferred timestamp and sometimes its the current time; it’d be nice if all the 00:00:00 timestamps are replaced except for when you’re back-adding data or something.)

Trello link: (leave in blank)

It does that if you edit any info too, even just put it on a custom list. It wipes whatever time data it has from marking it “Finished” and sets it to midnight that day. Which is fine when I’m backdating stuff but a little annoying otherwise