Timezones

Understanding U.S. Time Zones in Trucking

Time zone management is a critical skill for truck dispatchers. Pickup and delivery appointments span four continental time zones, and confusion about time can result in late deliveries, missed appointments, detention charges, and unhappy customers. Understanding how time zones work—and how daylight saving time affects operations—is essential for successful dispatching.

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The Four Continental U.S. Time Zones

1. Eastern Time Zone (ET) - UTC-5/UTC-4

States Covered:

• Fully in ET: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida (most), West Virginia, Ohio, Michigan (most)

Partial States:

• Kentucky: Eastern (most of state) and Central (western counties)
• Tennessee: Eastern (east) and Central (west, including Nashville, Memphis)
• Indiana: Eastern (most) and Central (northwest and southwest corners)
• Florida: Eastern (most) and Central (panhandle)

Major Cities:

• New York City, Boston, Philadelphia, Baltimore, Washington DC, Atlanta, Miami, Charlotte, Detroit, Cleveland

Importance for Dispatchers:

• ✅ Largest population - Most freight origins/destinations
• ✅ Business hours: 9 AM - 5 PM ET is the standard
• ✅ When calling brokers/shippers: Check if they're ET
• ✅ Most shipper/receiver hours posted in local time

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2. Central Time Zone (CT) - UTC-6/UTC-5

States Covered:

• Fully in CT: Wisconsin, Illinois (most), Michigan (4 western counties), Indiana (northwest/southwest), Alabama, Mississippi, Louisiana, Arkansas, Missouri, Iowa, Minnesota, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Texas (most)

Partial States:

• Tennessee: Western (Nashville, Memphis)
• Kentucky: Western counties
• Texas: Most in CT, but El Paso area is MT
• Florida: Panhandle (Pensacola area)
• Kansas: Most in CT, but 4 western counties in MT

Major Cities:

• Chicago, Houston, Dallas, San Antonio, New Orleans, Memphis, Nashville, Kansas City, Minneapolis, St. Louis

Importance for Dispatchers:

• ✅ Chicago is THE major hub - Always confirm CT vs ET
• ✅ Texas freight - Houston/Dallas on CT
• ✅ 1 hour behind ET - If broker calls at 10 AM CT, it's 11 AM ET
• ✅ Agricultural states - Harvest season scheduling

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3. Mountain Time Zone (MT) - UTC-7/UTC-6

States Covered:

• Fully in MT: Montana, Wyoming, Colorado, New Mexico, Utah, Idaho (most)

Partial States:

• Arizona: Does NOT observe DST (explained below)
• Nevada: Some eastern counties
• Texas: El Paso area
• Kansas: 4 western counties
• North Dakota: Southwest corner
• Oregon: Eastern county (Malheur)

Major Cities:

• Denver, Phoenix*, Salt Lake City, Albuquerque, El Paso, Boise
• *Phoenix on MT but doesn't observe DST

Importance for Dispatchers:

• ⚠️ Arizona is confusing - No DST (see below)
• ✅ 2 hours behind ET - Critical for cross-country coordination
• ✅ Lower freight density - Fewer shipments, careful scheduling
• ✅ Denver as major hub - Distribution center

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4. Pacific Time Zone (PT) - UTC-8/UTC-7

States Covered:

• Fully in PT: California, Washington, Oregon (most), Nevada (most)

Partial States:

• Idaho: Northern counties (Boise is MT)
• Oregon: Most in PT, one eastern county in MT

Major Cities:

• Los Angeles, San Francisco, San Diego, San Jose, Seattle, Portland, Las Vegas

Importance for Dispatchers:

• ✅ Major freight market - Ports, agriculture, tech
• ✅ 3 hours behind ET - Huge coordination challenge
• ✅ LA/Long Beach ports - Massive import gateway
• ✅ Business hours mismatch - PT 9 AM = ET 12 PM (noon)

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Time Zone Conversion Quick Reference

When it's...	ET	CT	MT	PT
12:00 PM (Noon)	12 PM	11 AM	10 AM	9 AM
3:00 PM	3 PM	2 PM	1 PM	12 PM
5:00 PM	5 PM	4 PM	3 PM	2 PM
6:00 AM	6 AM	5 AM	4 AM	3 AM

Quick Math:

• ET → CT: Subtract 1 hour
• ET → MT: Subtract 2 hours
• ET → PT: Subtract 3 hours
• PT → ET: Add 3 hours

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Daylight Saving Time (DST)

What is Daylight Saving Time?

Definition: Daylight Saving Time is the practice of moving clocks forward 1 hour in spring and back 1 hour in fall to make better use of daylight.

The Phrase:

• "Spring Forward, Fall Back"
• Spring: Clocks move forward (lose 1 hour of sleep)
• Fall: Clocks move back (gain 1 hour of sleep)

DST Schedule:

Starts (Spring Forward):

• Second Sunday in March
• 2:00 AM → 3:00 AM (skip 2:00-2:59 AM)
• Example: March 10, 2024 at 2:00 AM

Ends (Fall Back):

• First Sunday in November
• 2:00 AM → 1:00 AM (repeat 1:00-1:59 AM)
• Example: November 3, 2024 at 2:00 AM

Standard Time vs. Daylight Time:

Standard Time (Winter - Nov to Mar):

• Eastern Standard Time (EST) - UTC-5
• Central Standard Time (CST) - UTC-6
• Mountain Standard Time (MST) - UTC-7
• Pacific Standard Time (PST) - UTC-8

Daylight Time (Summer - Mar to Nov):

• Eastern Daylight Time (EDT) - UTC-4
• Central Daylight Time (CDT) - UTC-5
• Mountain Daylight Time (MDT) - UTC-6
• Pacific Daylight Time (PDT) - UTC-7

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Arizona - The Exception

Arizona Does NOT Observe DST

Why? Arizona opted out of DST in 1968 because:

• Desert state with extreme summer heat
• Extra daylight in evening = more air conditioning use
• Energy savings of DST didn't make sense

How It Works:

Winter (Nov - Mar): Arizona = Mountain Standard Time (MST)

• Same as MT (Colorado, New Mexico, Utah)
• 2 hours behind ET

Summer (Mar - Nov): Arizona = Mountain Standard Time (MST)

• But MT states move to MDT
• Arizona is now same as Pacific Time (PT)
• Still 2 hours behind ET, but now 1 hour behind MT states

The Confusion:

Season	AZ Time	MT States	Relationship
Winter	MST (UTC-7)	MST (UTC-7)	Same time
Summer	MST (UTC-7)	MDT (UTC-6)	AZ is 1 hour behind

Dispatcher Impact:

Winter Example:

• Denver (MT): 10:00 AM
• Phoenix (AZ): 10:00 AM
• ✅ Same time

Summer Example:

• Denver (MDT): 10:00 AM
• Phoenix (MST): 9:00 AM
• ⚠️ Phoenix is 1 hour behind!

Pro Tip: During summer, treat Arizona like Pacific Time for scheduling purposes.

Navajo Nation Exception to the Exception:

The Navajo Nation (northeastern Arizona) DOES observe DST because the reservation extends into New Mexico and Utah, which observe DST. This creates a time zone "island" within Arizona during summer.

Practical Impact: Minimal for trucking, but if delivering to Navajo Nation, confirm time zone.

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Hawaii and Alaska (Non-Continental)

Hawaii-Aleutian Time Zone (HT) - UTC-10

• Hawaii does NOT observe DST
• 5-6 hours behind ET (depending on DST)
• Limited trucking relevance (island state)

Alaska Time Zone (AKT) - UTC-9/UTC-8

• Alaska observes DST
• 4-5 hours behind ET
• Limited trucking to/from Lower 48

Dispatcher Note: Hawaii and Alaska freight is usually air or ocean, not truck.

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Common Time Zone Mistakes & How to Avoid Them

❌ Mistake #1: Assuming Broker is in ET

Problem: You call a broker at 9 AM your time (ET), but broker is in California (PT) - it's 6 AM there, and they're not in the office yet.

Solution:

• ✅ Always check broker's area code or city
• ✅ Look up broker's location online
• ✅ Best calling hours: 10 AM - 4 PM ET (covers all time zones during business hours)

❌ Mistake #2: Confirming Appointment Time Without Clarifying Time Zone

Problem: Shipper says "pickup at 2 PM" - you think 2 PM ET, but they meant 2 PM local (CT). Driver shows up at wrong time.

Solution:

• ✅ Always confirm: "That's 2 PM Central Time, correct?"
• ✅ Write in rate confirmation: "Pickup: 2:00 PM CST"
• ✅ Use 24-hour format if possible: "14:00 CST"

❌ Mistake #3: Not Accounting for DST Change

Problem: You schedule a load during the week DST changes. Driver loses/gains an hour unexpectedly.

Solution:

• ✅ Mark calendars: 2nd Sunday March, 1st Sunday November
• ✅ Plan around it: Avoid tight appointments that weekend
• ✅ Remind drivers: Send message Friday before DST change

❌ Mistake #4: Arizona Confusion in Summer

Problem: You dispatch a load to Phoenix assuming Mountain Time, but in summer Phoenix is effectively Pacific Time.

Solution:

• ✅ Remember: Arizona = PT in summer, MT in winter
• ✅ Always confirm with Phoenix contacts: "What time zone are you currently in?"
• ✅ Use online time converter to double-check

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Dispatcher Best Practices for Time Zones

1. Always Specify Time Zone in Documentation

Rate Confirmations Should Include:

Pickup: March 15, 2024 @ 08:00 CST
Delivery: March 17, 2024 @ 14:00 PST

Not:

Pickup: March 15 @ 8 AM  ❌ (Which time zone?)

2. Use 24-Hour Time Format to Avoid AM/PM Confusion

Better:

• 14:00 PST (no confusion)

Can be confusing:

• 2:00 PM PST vs. 2:00 AM PST (easy to misread)

3. Convert All Times to Driver's Current Location

Example: Driver is in Texas (CT), needs to be in California (PT) for 10 AM PT pickup.

Tell driver: "You need to arrive by 10 AM Pacific Time, which is 12 PM (noon) your current time in Texas."

4. Build in Buffer Time for Cross-Time-Zone Runs

Example:

• Pickup in NY (ET) at 8 AM, 3,000 miles to LA (PT)
• 3 hours time difference means driver "gains" 3 hours on clock
• Factor this into your transit time calculations

Cross-Country Math:

• 3,000 miles ÷ 50 mph average = 60 hours drive time
• Plus 3-hour time zone adjustment = affects appointment feasibility

5. Know Broker/Shipper Business Hours by Time Zone

Standard Business Hours:

• Eastern: 9 AM - 5 PM ET
• Central: 9 AM - 5 PM CT (10 AM - 6 PM ET)
• Mountain: 9 AM - 5 PM MT (11 AM - 7 PM ET)
• Pacific: 9 AM - 5 PM PT (12 PM - 8 PM ET)

Best Time to Call Everyone: 12 PM - 3 PM ET

• ET: Mid-afternoon
• CT: Late morning to early afternoon
• MT: Late morning
• PT: Early morning to late morning

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Real-World Time Zone Scenarios

Scenario 1: Coast-to-Coast Load

Load Details:

• Pickup: Newark, NJ (ET) - Thursday 6 PM
• Delivery: Los Angeles, CA (PT) - Saturday 10 AM
• Distance: 2,800 miles

Time Analysis:

• Pickup: Thursday 6 PM ET = 3 PM PT
• Delivery: Saturday 10 AM PT = 1 PM ET
• Available time: Thursday 6 PM ET to Saturday 1 PM ET = 43 hours
• Drive time needed: 2,800 miles ÷ 50 mph = 56 hours
• Verdict: ❌ NOT DOABLE - Need team drivers or more time

Scenario 2: Texas to Chicago

Load Details:

• Pickup: Houston, TX (CT) - Monday 8 AM
• Delivery: Chicago, IL (CT) - Tuesday 2 PM
• Distance: 1,100 miles

Time Analysis:

• Both in Central Time = easy planning
• Available time: 30 hours
• Drive time: 1,100 ÷ 50 = 22 hours
• Verdict: ✅ DOABLE - 8 hours buffer for breaks, fuel, delays

Scenario 3: Phoenix to Denver (Summer)

Load Details:

• Pickup: Phoenix, AZ - Tuesday 10 AM local
• Delivery: Denver, CO - Tuesday 6 PM local
• Distance: 850 miles

Time Analysis (Summer - DST Active):

• Phoenix: 10 AM MST (no DST)
• Denver: 10 AM MDT (observing DST) = actually 11 AM Phoenix time equivalent
• Pickup: 10 AM Phoenix = 11 AM Denver
• Delivery: 6 PM Denver = 5 PM Phoenix
• Actual available time: 11 AM to 6 PM Denver time = 7 hours
• Drive time: 850 ÷ 50 = 17 hours
• Verdict: ❌ NOT DOABLE - Impossible timeline

If this was Winter (No DST Difference):

• 10 AM Phoenix = 10 AM Denver
• Delivery 6 PM Denver = 6 PM Phoenix
• Available: 8 hours
• Still not doable, but time zone isn't making it worse

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Time Zone Tools for Dispatchers

Online Time Zone Converters:

World Time Buddy:

• Website: worldtimebuddy.com
• Compare multiple time zones visually
• Shows DST status

Time and Date:

• Website: timeanddate.com
• Time zone converter
• Meeting planner for multiple zones

Google:

• Search: "time in [city]"
• Instant current time display

Phone Features:

Add Multiple Clocks:

• iPhone: Clock app → World Clock
• Android: Clock app → Clock tab
• Add: New York (ET), Chicago (CT), Denver (MT), Los Angeles (PT)

Quick Reference: Glance at phone to see all 4 time zones instantly

Dispatcher Software:

Most TMS (Transportation Management Systems) include:

• Automatic time zone detection
• Appointment scheduling with time zone indicators
• Reminders adjusted for time zones

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Time Zone Impact on Hours of Service (HOS)

HOS and Time Zones:

Federal Regulations: Hours of Service are based on the truck's current location time zone, not driver's home time zone.

Example:

• Driver starts in New York (ET) at 6 AM ET
• Drives to Illinois (CT)
• 14-hour clock started at 6 AM ET
• When driver reaches Illinois (CT), it's now 1 hour earlier on the clock
• But HOS still expires 14 hours from 6 AM ET

ELD (Electronic Logging Device) Handling:

• Modern ELDs automatically adjust for time zone crossings
• Hours countdown continues regardless of time zone
• Dispatcher must account for this when planning routes

Practical Impact: Crossing multiple time zones doesn't give driver "extra hours" - the 14-hour clock keeps running.

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Daylight Saving Time: Dispatcher Survival Guide

DST Change Weekends - What to Expect:

Spring Forward (March):

• Clocks jump from 2:00 AM → 3:00 AM
• You lose 1 hour
• Early morning deliveries (2 AM - 6 AM) can be confusing
• Driver "loses" an hour of available time

Fall Back (November):

• Clocks fall from 2:00 AM → 1:00 AM
• You gain 1 hour
• 1:00 AM - 2:00 AM happens twice
• Driver "gains" an hour

Dispatcher Strategy for DST Weekends:

Avoid Scheduling:

• ❌ Tight appointments Saturday night / Sunday morning
• ❌ Time-sensitive loads that weekend
• ❌ Critical customer deliveries (too many variables)

If You Must Schedule:

• ✅ Add 2-hour buffer to appointments
• ✅ Confirm with driver they know about DST
• ✅ Communicate with receiver about potential confusion
• ✅ Use UTC time for precision (doesn't change with DST)

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Conclusion

Time zone management is a fundamental dispatcher skill that separates professionals from amateurs. Mistakes cost money, damage customer relationships, and frustrate drivers.

Key Takeaways:

Master These Concepts:

• ✅ Four continental time zones: ET, CT, MT, PT
• ✅ DST dates: 2nd Sunday March (forward), 1st Sunday November (back)
• ✅ Arizona exception: No DST, effectively PT in summer
• ✅ Always specify time zone in all communications
• ✅ Convert times for drivers to their current location
• ✅ Build buffer time for cross-time-zone loads

Avoid These Mistakes:

• ❌ Assuming broker/shipper time zone
• ❌ Not confirming "local time" in appointments
• ❌ Forgetting Arizona doesn't observe DST
• ❌ Scheduling tight appointments during DST change weekends

Professional Habits:

• Document everything with time zones (CST, PST, etc.)
• Use 24-hour format when possible (14:00 vs. 2 PM)
• Double-check conversions with online tools
• Add world clocks to your phone
• Communicate clearly with drivers about time expectations

"Time zone mistakes are 100% preventable with proper communication and attention to detail. The professionals never confuse time zones."

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Continue Learning:

• States and their importance
• Understanding the Trucking Industry
• Markets

Master time zones to avoid costly mistakes. Successful dispatchers never lose track of time—or time zones. Continue your education at Carriversity.