What is Eastern Time in UTC?

Eastern Standard Time is UTC−5; Eastern Daylight Time is UTC−4 when DST applies.

Does Hawaii observe daylight saving time?

Hawaii generally remains on Hawaii-Aleutian Standard Time year-round.

Does Arizona observe daylight saving time?

Most of Arizona does not observe DST, though the Navajo Nation follows different rules.

Is this a live clock?

The displayed clock updates from your browser, not from a guaranteed atomic time source.

Can I use this for an appointment?

Use it for orientation, then confirm the official local time zone for important schedules.

Free Online GIS Utility

Zero Sign-Up & Client-Side Privacy

WGS84 Ellipsoidal Geodesics

US Time Zone Map

Interactive map of US time zones (Eastern, Central, Mountain, Pacific, Alaska, Hawaii) with current live times.

Direct Answer & Core Functionality

The US time zone map groups the states into Eastern, Central, Mountain, Pacific, Alaska, and Hawaii-Aleutian time zones, with standard and daylight offsets shown for quick reference.

Zones shown

US time-zone groups

Clock

2:17:34 PM

Your browser's local clock

Reference

UTC offsets

Standard / daylight notation

Selected US time zone

Eastern

UTC−5 / UTC−4

Example places: New York, Atlanta

*Arizona generally observes Mountain Standard Time year-round. Actual boundaries and daylight-saving rules can vary by state, county, and tribal jurisdiction; verify official local time for critical schedules.

US Time Zones Technical Specifications & Standards

Reference ISO / OGC Standard

Geodetic Datum

IANA time-zone concepts; simplified US group display.

Standard global ellipsoidal coordinate reference system

Mathematical Engine

US Geodesics

Reference guide, not an authoritative scheduling service.

Vector & Data Exports

GeoJSON · KML · CSV · SVG

Compatible with QGIS, ArcGIS, Google Earth & CAD

Privacy & Processing

100% Client-Side

Calculations run in-browser. Zero coordinate logging.

How to Use the US Time Zone Map

Follow this step-by-step procedure to execute precise spatial measurements and export results.

1
Choose a US zone: Select a zone pill or card to highlight it.
2
Read UTC offsets: Compare standard and daylight-saving offsets for the selected zone.
3
Check local rules: Use official state or time-zone sources for critical appointments because boundaries and DST rules vary.

Accuracy & Benchmark Standard

Geodesic Precision vs. Competitor Mapping Approaches

Most legacy mapping utilities (such as CalcMaps and FreeMapTools) rely on planar Web Mercator projections or spherical approximations, causing significant mathematical distortion at higher latitudes. GeoMap Suite computes exact ellipsoidal geodesics on the WGS84 reference ellipsoid.

Calculation Model	Mathematical Basis	Distortion on WGS84	Standard Tools	Practical Application
Planar (Web Mercator)	Cartesian dx² + dy²	10% to 200%+ error	CalcMaps / Simple map tools	Distorts drastically away from equator. Inaccurate for true distance.
Spherical Great-Circle	Haversine (R = 6,371 km)	Up to 0.5% (~5 km/1,000 km)	Basic Google Maps wrappers	Ignores Earth's polar flattening. Reasonable for rough estimates.
GeoMap Suite Ellipsoidal	Karney Direct/Inverse WGS84	< 15 nanometers (<0.0001%)	GeoMap Suite	Geodetic surveying, maritime, flight paths & legal boundary analysis.

Compare New York and California

A remote team checks the major US zone difference.

Input Parameters

Eastern: UTC−5 / UTC−4
Pacific: UTC−8 / UTC−7

Computed Outputs

Typical difference: 3 hours

Step-by-Step Mathematical Process

Select Eastern.
Select Pacific.
Compare the displayed offsets.

Practical Takeaway: The exact difference depends on daylight-saving dates and local exceptions.

Understanding Your Results & Practical Interpretation

Standard versus daylight time

A zone may show two offsets because many US jurisdictions shift clocks seasonally. Arizona and Hawaii are important exceptions.

Use official sources for critical timing

This page is a visual reference. Confirm local rules with the relevant government, airline, school, or event organizer.

Practical Applications & Real-World Use Cases

Distributed teams

Remote-team planning

Compare common US zone offsets at a glance.

Students and teachers

Geography lessons

Learn why time zones cross state boundaries.

Mathematical Methodology & Geodetic Accuracy

US time-zone reference groups

The tool presents common US zone groups and browser time, with standard/daylight UTC notation.

local time = UTC + zone offset

Geodetic Datum & Reference FrameIANA time-zone concepts; simplified US group display.

Theoretical Computation PrecisionReference guide, not an authoritative scheduling service.

Limitations & Boundary Conditions

•State and county boundaries can split time zones.
•Daylight-saving rules change by jurisdiction and date.
•The browser clock is not a time-sync guarantee.

Authoritative Reference Standards

IANA Time Zone Database US DOT time zone information Explore Geospatial Blog & Studies →

Troubleshooting & Geographic Edge Cases

Why does Arizona differ from other Mountain states?

Most of Arizona does not observe daylight saving time, so its offset can differ seasonally from neighboring states.

Are all state boundaries identical to time-zone boundaries?

No. Some states and counties are split, and local exceptions exist.

Frequently Asked Questions

This guide shows six common US groups: Eastern, Central, Mountain, Pacific, Alaska, and Hawaii-Aleutian.

Reviewed by: GeoMapSuite Editorial Team (Time-zone reference review)Last Reviewed: 2026-09-22 • Revision us-time-zone-map-v1