My favorite is a fun little time thing--Arizona, somewhat famously does not recognise DST, unlike surrounding states, so in the summer it is no longer mountain time. inside AZ, is the Navajo Nation (which is also in the three other sourrounding states.) The Navajo Nation does recognise DST, so in the summer, if you're driving through AZ, and head northeast, you'll have to change your watch befroe you leave the state. Then, completely surrounded by the navajo nation is the Hopi Nation. the Hopi do not recognize DST like Arizona.