US time zones for truckers and dispatchers

Six zones, fourteen states split down the middle, and one state that ignores daylight saving entirely. Here is the map, where the interstates cross, and the mistakes that cost people a delivery window.

Updated 26 September 2026 · about a 6 minute read

The map

Colour shows each state's main zone. The fourteen states the boundary actually runs through are hatched — because a time zone line follows county lines, not state lines, and colouring Texas a single colour would be telling you El Paso is on Central time. Hover any state for its zone.

AK — Alaska / Hawaii-Aleutian — split AL — Central AR — Central AZ — Mountain — no daylight saving CA — Pacific CO — Mountain CT — Eastern DC — Eastern DE — Eastern FL — Eastern / Central — split GA — Eastern HI — Hawaii-Aleutian IA — Central ID — Mountain / Pacific — split IL — Central IN — Eastern / Central — split KS — Central / Mountain — split KY — Eastern / Central — split LA — Central MA — Eastern MD — Eastern ME — Eastern MI — Eastern / Central — split MN — Central MO — Central MS — Central MT — Mountain NC — Eastern ND — Central / Mountain — split NE — Central / Mountain — split NH — Eastern NJ — Eastern NM — Mountain NV — Pacific / Mountain — split NY — Eastern OH — Eastern OK — Central OR — Pacific / Mountain — split PA — Eastern RI — Eastern SC — Eastern SD — Central / Mountain — split TN — Central / Eastern — split TX — Central / Mountain — split UT — Mountain VA — Eastern VT — Eastern WA — Pacific WI — Central WV — Eastern WY — Mountain NWNNEWESWSSE
Pacific Mountain Central Eastern Alaska Hawaii-Aleutian Split between two zones

Boundaries: US Census Bureau cartographic files (public domain), Albers USA projection. Colour shows each state's main zone; hatching marks the fourteen states the boundary cuts through. Alaska and Hawaii are insets, not to scale.

The six zones

ZoneStandardDaylightRoughly
Eastern (ET)UTC−5UTC−4East coast to Ohio and Georgia
Central (CT)UTC−6UTC−5Gulf coast up through the Midwest
Mountain (MT)UTC−7UTC−6Rockies and the high plains
Pacific (PT)UTC−8UTC−7West coast
Alaska (AKT)UTC−9UTC−8Alaska
Hawaii-Aleutian (HST)UTC−10no DSTHawaii, far Aleutians

Running west you gain an hour at each boundary; running east you lose one. On a coast-to-coast run that is three hours either way — which is a full extra shift of daylight, or a delivery window missed by three hours if you plan in the wrong clock.

The fourteen split states

This is the part most time zone maps get wrong. Zone boundaries follow county lines, not state lines. Colour Texas one colour and you have just told someone El Paso is on Central time. It is not.

StateSplitWhat it means on the road
TexasCentral / MountainEl Paso and Hudspeth County are Mountain; everything else is Central
FloridaEastern / CentralThe panhandle west of the Apalachicola River is Central
IndianaEastern / CentralThe north-west corner near Chicago and the south-west near Evansville are Central
KentuckyEastern / CentralLouisville and east are Eastern; Bowling Green and west are Central
TennesseeEastern / CentralKnoxville and Chattanooga are Eastern; Nashville and Memphis are Central
MichiganEastern / CentralFour counties in the western Upper Peninsula are Central
North DakotaCentral / MountainRoughly west of the Missouri River is Mountain
South DakotaCentral / MountainRoughly west of the Missouri River is Mountain
NebraskaCentral / MountainThe panhandle west of North Platte is Mountain
KansasCentral / MountainFour counties in the far west are Mountain
IdahoPacific / MountainThe northern panhandle is Pacific; Boise and the south are Mountain
OregonPacific / MountainMost of Malheur County in the far east is Mountain
NevadaPacific / MountainWest Wendover on the Utah line is Mountain
AlaskaAlaska / Hawaii-AleutianThe far western Aleutians run an hour behind

Where the interstates change zone

Approximate crossing points on the long hauls. Use them for planning; for an exact mile marker on a specific run, the calculator works it out from the actual route.

RouteZone changes, west to east
I-10Pacific → Mountain at Blythe, CA · Arizona stays on standard time year round · Mountain → Central just west of Van Horn, TX · Central → Eastern at the Apalachicola River in the Florida panhandle
I-40Pacific → Mountain at Needles, CA · Mountain → Central at the Texas/New Mexico line near Glenrio · Central → Eastern around the Tennessee River in west Tennessee
I-70Mountain → Central near Goodland, KS · Central → Eastern at the Indiana/Illinois line near Terre Haute
I-80Pacific → Mountain at the Nevada/California line · Mountain → Central around North Platte, NE · Central → Eastern near the Indiana/Illinois line
I-90Pacific → Mountain in the Idaho panhandle near Lookout Pass · Mountain → Central around the Missouri River in South Dakota · Central → Eastern near the Indiana/Illinois line
I-94Mountain → Central just west of Bismarck, ND · Central → Eastern near the Michigan/Indiana line
I-20Central → Eastern at the Alabama/Georgia line

The Arizona trap

Arizona does not observe daylight saving. From March to November it matches Pacific time, not Mountain. A dispatcher in Dallas booking an 0800 Phoenix delivery in July is booking it for 0600 their own time — two hours earlier than the Mountain-time arithmetic suggests, not one.

Full answer on Arizona's time zone, including a live Arizona clock and how it lines up with California and Denver through the year.

The exception to the exception: the Navajo Nation in north-eastern Arizona does observe daylight saving, and the Hopi Reservation inside it does not. If you are running US-160 or US-191 in summer, the clock can change twice in an hour.

Hawaii also skips daylight saving, and so does Saskatchewan if you run into Canada — it sits on Central time all year, which means it matches Mountain in summer.

Which clock does what

The thingRuns on
Your 11-hour, 14-hour and 70-hour clocksHome terminal time. Crossing a zone does not move them
Your ELD logHome terminal time, same as above
Pickup and delivery appointmentsThe facility's local time, almost always
The 34-hour restart's two 1am–5am periodsHome terminal time
Broker check calls and after-hours numbersThe broker's office time — ask which

The one that catches people: your HOS clock does not reset or shift at a zone boundary. Drive west across three zones and your 14-hour window still ends 14 hours after it started in terminal time, even though the wall clock says you have gained three hours. The daylight is free; the clock is not.

Daylight saving dates

Clocks go forward one hour at 2am local on the second Sunday in March, and back one hour at 2am local on the first Sunday in November. On the spring night you lose an hour of your 14-hour window against the wall clock; on the autumn night you gain one. Arizona, Hawaii and Saskatchewan sit both of them out.

Common questions

How many time zones does the United States have?
Six that matter for trucking: Eastern, Central, Mountain, Pacific, Alaska and Hawaii-Aleutian. Including the territories there are nine in total, but no truck drives to them.
Which US states are in two time zones?
Fourteen: Alaska, Florida, Idaho, Indiana, Kansas, Kentucky, Michigan, Nebraska, Nevada, North Dakota, Oregon, South Dakota, Tennessee and Texas. The boundary follows county lines, not the state line, which is why a map coloured by state gives the wrong answer in those fourteen.
Does Arizona observe daylight saving time?
No. Arizona stays on Mountain Standard Time all year, except the Navajo Nation in the north-east, which does observe daylight saving. For eight months of the year Arizona matches Pacific time rather than Mountain, which is the single most common appointment mistake in dispatch.
Which time zone does my hours-of-service clock run on?
Your home terminal's time zone. The 14-hour window, the 11-hour driving limit and the 70-hour cycle are all counted in terminal time, and they do not reset or shift when you cross a time zone. Only the clock on the wall changes.
What time zone is a pickup or delivery appointment in?
Almost always the facility's local time, not yours and not the broker's. If the rate confirmation does not say, ask. A 0800 appointment booked from a Dallas office for a Phoenix receiver is two hours earlier than it looks in summer.
When do the clocks change in the United States?
Daylight saving starts on the second Sunday in March, when clocks go forward an hour at 2am local, and ends on the first Sunday in November, when they go back. Arizona and Hawaii do not take part.

Stop doing this in your head

Put a lane into the calculator and it shows the local time at both ends, where the route changes zone, and your arrival in the receiver's clock — free, no signup.

Open the calculator