Some Trac installations respect Accept-Language, and parse the date accordingly. So 11/3/15 could be either November 3rd or March 11th. Formatting the date as 2015-11-03 works regardless of user language.
Created attachment 264724 [details] proposed fix
Comment on attachment 264724 [details] proposed fix Clearing flags on attachment: 264724 Committed r191988: <http://trac.webkit.org/changeset/191988>
All reviewed patches have been landed. Closing bug.