<Li> Most use the standard time for their zone (or zones, where a state is divided between two zones), except for using daylight saving time during the summer months . Originally this ran from the last Sunday in April until the last Sunday in October . Two subsequent amendments, in 1986 and 2005, have shifted these days so that daylight saving time now runs from the second Sunday in March until the first Sunday in November . Arizona time zones </Li> <Li> Arizona and Hawaii use standard time throughout the year . However: <Ul> <Li> The Navajo Nation observes DST throughout its entire territory, including the portion that lies in Arizona . But the Hopi Nation, which is entirely surrounded by the Navajo Nation and is entirely in Arizona, does not observe DST . (See map inset right .) </Li> </Ul> </Li> <Ul> <Li> The Navajo Nation observes DST throughout its entire territory, including the portion that lies in Arizona . But the Hopi Nation, which is entirely surrounded by the Navajo Nation and is entirely in Arizona, does not observe DST . (See map inset right .) </Li> </Ul> <Li> The Navajo Nation observes DST throughout its entire territory, including the portion that lies in Arizona . But the Hopi Nation, which is entirely surrounded by the Navajo Nation and is entirely in Arizona, does not observe DST . (See map inset right .) </Li>

Where does it change from mountain time to central time