Board Thread:Support Requests - Getting Technical/@comment-24652145-20151030100012/@comment-24757753-20151030101617

The badges (and most everything else) work using UTC, not your local time. Edit times are shown in UTC by default (e.g. when logged-out), but you've probably set your settings to show in local time, meaning you'll see different times logged-in.

Sorry to say, it's not really a bug - you've got to edit every day according to UTC, not your local timezone.