I have installed the brand-new OD 1.9b536 and configured amongst others the Weather docklet.
Unfortunately, the flyouts of the 5-day forecast show the wrong days. For instance, today is monday 18 June, 2007. The flyouts show "Today", "Tomorrow", "Tuesday", "Wednesday" and "Thursday". It should be "Today", "Tomorrow", "Wednesday", "Thursday" and "Friday".
In Windows' Regional Options I have set my "Location" to "Italy", in "Date and Time Settings" my time zone is correctly set to "GMT+1 Amsterdam, Rome,...". All other settings respect my geographical position. The location chosen is the setup is either "Lugano, Switzerland" or "Milano, Italy" both found but also giving the same "error".
Late at night the docklet magically "recovers" giving the proper days on the flyouts, but the next day I have the same problem again. This makes me think that the weather docklet has embedded its own time zone. This qualifies for me as a bug.
Since I was annoyed by this behaviour, I have installed the XMLWeather docklet in place (picking up from weather.com using code 'ITXX0082') the indication is correct but unfortunately there are no flyouts with 5-day forecast.