How to Read US Time Zones for Work Schedule Planning
Ever tried to schedule a meeting across multiple time zones and ended up with someone joining at 7 AM or 9 PM? Time zones can be tricky, but once you know the basics, they’re actually manageable.
The US spans six time zones from Eastern to Hawaii-Aleutian, with Eastern Time three hours ahead of Pacific Time and daylight saving running from the second Sunday in March to the first Sunday in November.
The six US time zones
| Zone | Abbreviation | Standard offset | DST offset | Major cities |
|---|---|---|---|---|
| Eastern | ET | UTC-5 | UTC-4 | New York, Atlanta, Miami |
| Central | CT | UTC-6 | UTC-5 | Chicago, Houston, Dallas |
| Mountain | MT | UTC-7 | UTC-6 | Denver, Phoenix, Salt Lake City |
| Pacific | PT | UTC-8 | UTC-7 | Los Angeles, Seattle, San Francisco |
| Alaska | AKT | UTC-9 | UTC-8 | Anchorage, Fairbanks |
| Hawaii-Aleutian | HST | UTC-10 | (no DST) | Honolulu |
Hawaii and most of Arizona skip daylight saving time entirely. Everywhere else springs forward in March and falls back in November.
Daylight saving time rules
DST in the US runs from the second Sunday in March to the first Sunday in November. In 2026 those dates are March 8 and November 1.
During DST:
- ET becomes EDT (UTC-4)
- CT becomes CDT (UTC-5)
- MT becomes MDT (UTC-6)
- PT becomes PDT (UTC-7)
The gap between ET and PT stays at 3 hours year-round, but the gap between US zones and overseas zones (like London or Tokyo) shifts by an hour twice a year, which is when international meetings break.
Actually, I once scheduled a meeting with a team in London during DST transition week. The invite said “10 AM ET” but I forgot London hadn’t sprung forward yet, so they joined at 3 PM instead of 4 PM. Total chaos.
Reading the abbreviations correctly
The abbreviations are ambiguous unless you know the date:
- “EST” means Eastern Standard Time (UTC-5), in effect late fall through winter
- “EDT” means Eastern Daylight Time (UTC-4), in effect spring through early November
- “ET” is a catch-all meaning “Eastern Time, whatever is in effect”
For scheduling, write “9 AM ET” rather than “9 AM EST” unless you specifically mean the winter offset. Mixing EST and EDT in the same invitation is a common cause of missed calls.
Worked example: scheduling a 2 PM ET call
A team wants a 2 PM ET call. Local equivalents on a standard summer day:
- 2 PM ET (New York)
- 1 PM CT (Chicago)
- 12 PM MT (Denver)
- 11 AM PT (Los Angeles)
- 10 AM AKT (Anchorage)
- 8 AM HST (Honolulu)
The same call works for everyone except Hawaii, where 8 AM is early but doable. A 4 PM ET call, by contrast, would land at 1 PM PT — fine — but 10 AM HST the next day if pushed past midnight, which is why Hawaii teams often get shortchanged.
”9 AM ET” vs “9 AM local”
These are different instructions:
- 9 AM ET means everyone dials in at the same absolute instant. People in different zones join at their own local equivalent.
- 9 AM local means everyone joins at 9 AM wherever they sit. The East Coast and West Coast are never on the call at the same time.
Distributed teams usually pick one anchor zone (commonly ET) and stick with it. “9 AM local” works for asynchronous handoffs and shift coverage but not for live meetings.
Why Phoenix trips people up
Phoenix stays on Mountain Standard Time (UTC-7) all year. From March to November, when Denver shifts to MDT (UTC-6), Phoenix is actually one hour behind Denver, not on the same clock. A meeting set for “2 PM MT” means 2 PM in Denver but 1 PM in Phoenix during DST — a classic Arizona scheduling trap.
Does this mean you should avoid scheduling with Phoenix-based teams? Not at all — just remember to specify the zone. “2 PM MST” works year-round for Phoenix. “2 PM MDT” would be 1 PM in Phoenix during DST, which is probably not what you want.
For reliable conversions across all six zones including the Arizona quirk, use the US Time Zone Converter and read our guide to US time zones for remote work.
