[HideousKojima]

>As with all things time, I'm no expert, and could be wrong about something. If you are, please correct me!

Easy example that I have to deal with semi-regularly since I live and work in Mountain Time: Arizona. Arizona is under Mountain Time, but does not observe Daylight Savings. So America/Phoenix would work fine (and America/Denver for the rest of the Mountain Time zone) but simply using MT would not.

To complicate matters even more is that the Navajo reservation (which is partially in Arizona) observes DST, but the Hopi Reservation (also in Arizona, but completely surrounded by the Navajo Reservation) does not.