I'm sure a use case exists where you want to store a timezone, but I don't know what it is. I try and use UTC everywhere, and only worry about time zones when displaying.
Eastern Time Zone is a single time zone, that has different offsets depending on season, formally referred to as EDT and EST to make it easier to identify as daylight or standard references to UTC.
Even regions within the same time zone don't follow the standard exactly, so Panama does not observe daylight saving time while New York does. This is why we have even more granular settings used for calendars and dates.
You either just store UTC and co, or you store it just as an datetime + offset.
100% of apps in production don't handle most of the timezone intricacies anyway and the sky hasn't fallen (heck, the sky hasn't even fallen for Y2K).
100% of apps? You must not know what timezone intricacies are then or just how much effort is spent to make sure time itself is properly handled, especially in any major application that has global users.
You'd be surprised.
