[michaelt]

Arizona doesn't observe DST, but it contains the Navajo Nation which does[0], and in turn contains the Hopi Reservation which doesn't.

So you can go back and forth by an hour within a single US state.

[0]The Navajo Nation extends into Utah and New Mexico, which observe DST, so this lets the Navajo Nation maintain a single time throughout.

[hannasanarion]

There is actually a Navajo exclave inside the Hopi reservation, and a Hopi exclave inside the Navajo reservation, so if you travel into Arizona via route 264 in the summer, you have to change your clock seven times.

[FearNotDaniel]

I like this, in a crazy way, despite having argued elsewhere for consistency... Makes me wonder, if Italy and Austria ended up choosing different time zones, would the ethnic Austrians living in Süd-Tirol get their own time zone too?