Some CWOP weather station software don't follow strict APRS standard and assume that the server will append a date/time to the weather report. Which is asinine, since the server has no idea when the weather report was taken...only when it was received.
But, to support these situations we'll need to add a timestamp for reports that are missing that information and assume it's accurate. In which case we probably should also add a (?) to the timestamp in the display since we know the timestamp to be wrong.