Remember user selection of TimeZoneInfo in a cookie, property to use from C#?
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I have a DropDownList control that is populated with TimeZones from calling:

    ReadOnlyCollection<TimeZoneInfo> tzCollection;
    tzCollection = TimeZoneInfo.GetSystemTimeZones();

Now I want to add an option to remember a previous user selection in a persistent cookie but I can't figure out which parameter to use for that: I thought to use the time offset from GMT/UTC, but there might be several time zones in the list with the same offset. And using the TimeZoneInfo.Id property also seems bad to me because it is represented by descriptive string such as "Pacific Standard Time", which may pose a problem for localization (in case of foreign languages.)

So any suggestions what shall I use?