Default [Q] Automatic timezone for selected location

Hi all,
I have a problem when selecting override widget locality in that i cannot get the widget to give me the option of selecting the timezone for the city i want automatically. I manually changed the timezone for the widget once, and now whenever i try to change the location for the widget it defaults to that manually selected timezone, not the timezone for the new location.
I cant find the automatic timezone selection in the dropdown... Is there one..?
I have removed and replaced the widget but that has not made any difference.
Any help appreciated,
Cheers