Phoenix, United States · UTC-7 ☆

Phoenix is in the Mountain Standard Time timezone (MST/UTC-7), permanently, with no daylight saving time. Arizona is one of the few US states that never changes its clocks.

Arizona doesn’t change its clocks. While Los Angeles springs forward and falls back, while Denver adjusts twice a year, Phoenix stays fixed at UTC-7. Mountain Standard Time, always. No daylight saving time, a choice made in 1968 and never reversed.

The logic is desert logic. Phoenix summers are already punishing, regularly exceeding 43 degrees Celsius. Pushing sunset an hour later in July would mean an extra hour of brutal evening heat. The state decided it did not need more daylight in July.

The practical consequence is that Phoenix’s time relationship to the rest of the country shifts twice a year. In winter, Phoenix matches Denver and is two hours behind New York. In summer, when California and Colorado spring forward, Phoenix suddenly matches Los Angeles and is only three hours behind New York. The city stays still while everyone else moves.

the exception within the exception

The exception within the exception: the Navajo Nation, which covers a large portion of northeastern Arizona, does observe daylight saving time. The Hopi Reservation, surrounded by the Navajo Nation, does not. Drivers crossing these lands in summer pass through a patchwork of different clock-states.

9am in Phoenix is 4pm in London in winter, 5pm in summer.

Sources

• IANA Time Zone Database - America/Phoenix
• Arizona Department of Administration
• Navajo Nation Government