United States Time Zones
The contiguous United States uses 4 main time zones (Eastern, Central, Mountain, Pacific). Alaska and Hawaii each have their own zones. All US states except Arizona and Hawaii observe daylight saving time.
US Time Zone Guide
Eastern Time
ET — UTC−5 (EST)
Summer: UTC−4 (EDT)
Central Time
CT — UTC−6 (CST)
Summer: UTC−5 (CDT)
Mountain Time
MT — UTC−7 (MST)
Summer: UTC−6 (MDT)
Phoenix stays on MST year-round — no DST observed.
Pacific Time
PT — UTC−8 (PST)
Summer: UTC−7 (PDT)
Alaska Time
AKT — UTC−9 (AKST)
Summer: UTC−8 (AKDT)
Hawaii Time
No DSTHST — UTC−10 (HST)
Summer: No DST
Hawaii does not observe daylight saving time.
When Does the US Change Its Clocks?
US clocks spring forward by 1 hour on the first Sunday in March (at 2:00 AM local time) and fall back on the first Sunday in November (at 2:00 AM local time).
Arizona (except the Navajo Nation) stays on Mountain Standard Time (UTC−7) year-round. Hawaii stays on Hawaii-Aleutian Standard Time (UTC−10) year-round.
The US Senate passed the Sunshine Protection Act in 2022 to make DST permanent, but the bill did not pass the House of Representatives and seasonal clock changes continue as of 2025.