United States Time Zones Guide
US Eastern, Central, Mountain, Pacific, Alaska, Hawaii — DST rules and abbreviation pitfalls.
The contiguous US has four primary zones plus Alaska and Hawaii — six common IANA regions. **Never** rely on EST/CST alone: they blur standard vs daylight time, and Arizona mostly skips DST.
Main IANA zones
- America/New_York — Eastern (DC, NYC, Miami)
- America/Chicago — Central (Chicago, Dallas)
- America/Denver — Mountain (Denver, Salt Lake City)
- America/Los_Angeles — Pacific (LA, Seattle)
- America/Anchorage — Alaska
- Pacific/Honolulu — Hawaii (no DST)
Daylight saving
Most US regions spring forward 2 AM → 3 AM on the second Sunday in March and fall back on the first Sunday in November. Arizona (except Navajo Nation) stays fixed. See DST Guide for 2026 dates.