The continental U.S. crosses 5 time zones. From east to west they are:
Eastern (EST UTC-5/EDT UTC-4)
Central (CST UTC-6/CDT UTC-5)
Mountain (MST UTC-7/MDT UTC-6)
Pacific (PST UTC-8/PDT UTC-7)
Alaska (AKST UTC-9/AKDT UTC-8)
Note: The abbreviations stand for "Standard Time" and "Daylight saving Time"
Arizona falls within Mountain Standard Time, but much of the state does not observe daylight saving time.
Outside of the Continental region, the US islands and territories are in other time zones. Hawaii follows Hawaii Standard Time (HST UTC-10) with no observance of daylight saving. Alaska's Aleutian Islands observe Hawaii-Aleutian Time (HAST UTC-10/HADT UTC-9) and do follow daylight saving time. Puerto Rico is within the Atlantic Standard Time Zone (AST UTC-4) and Guam is in Chamorro Time Zone (CHST UTC+10). Neither of these territories observe daylight saving.
The US observes daylight saving time starting at 2:00 AM on the second Sunday in March and ending at 2:00 AM on the first Sunday in November.
To find the time in a specific location, use the search box above.