So you've written a gem of a post and you submit it.. then you go back to it and see a misspelled word (spell check is the ABC in the toolbar). After you go back in and edit your post the site leaves a "date stamp" at the bottom of your post. If, after editing your post you see that it needs more editing a "date stamp" will again be left at the bottom of the post when you submit it.. leaving two "date stamps" at the bottom of your post, and so on.
To get rid of redundant "edit tags" all you have to do is scroll to the bottom of the open post and delete them. Once you've removed all the redundant tags only a single current "date stamp" will show once you've hit submit.