Arizona is in the Mountain Time Zone, which means that Arizona should be two hours behind Columbus and other locations in the Eastern Time Zone. Yet, when we arrived in Tucson for our recent trip, we learned that it was three hours behind us. What gives?
It’s because Arizona doesn’t recognize Daylight Savings Time. As a result, Arizona swings from Mountain Time Zone time, during the part of the year when other states are on Standard Time, to Pacific Time Zone time when those states switch to Daylight Savings Time. The only exceptions to this are the portions of the Navajo Indian Reservation in Arizona; those areas follow Daylight Savings Time.
Arizona is officially part of the Mountain Time Zone, as a result of the 1918 Standard Time Act that established the American time zones. But Arizona’s effective time changes from Mountain to Pacific because Arizona asked for, and received, an exemption to the federal law that established Daylight Savings Time. According to the first article linked above, Arizona wanted to be excused from springing ahead and falling back because it gets hot there in the summer, and going to Daylight Savings Time–which means the sun doesn’t set until about 9 p.m.–would ensure that it stays hot until later in the day and defers any relief from the blazing temperatures.
It’s weird to think that one state can be excused from the time rules, but Arizona isn’t alone: Hawaii, Puerto Rico, Guam, American Samoa, and the U.S. Virgin Islands also don’t recognize Daylight Savings Time. Those other states and territories probably also have good reasons for their approach, too. That’s our federal system for you.