In the new Accounts tab, a user can have joined "today ago".
This is fixed now ago. Sorry about that — I didn't test exhaustively enough.
This problem resolves itself after 24 hours (at the latest). Please be patient for the server caching to catch up. After that time, "today ago" will become "yesterday ago" and eventually "2 days ago" (alternatively, "todays ago" according to reverse Polish notation).