Arizona operates on Mountain Standard Time (MST) year-round, which is 7 hours behind Coordinated Universal Time (UTC-7). Unlike most US states, Arizona does not observe daylight saving time, maintaining the same UTC offset throughout the year.
All of Arizona follows Mountain Standard Time, including Phoenix, Tucson, Mesa, Chandler, and Scottsdale. Note that the Navajo Nation within Arizona does observe daylight saving time. Arizona's decision to skip DST means it aligns with Pacific Time during summer months.
Arizona is unique for not observing daylight saving time. During summer, Arizona matches California's time (both UTC-7), but during winter, it matches Colorado's time. When it's noon in Phoenix, it could be noon in Denver or noon in Los Angeles, depending on the season.