A time zone is a region that follows the same civil time rules. Explore current UTC offsets, U.S. and world time zones, abbreviations, daylight saving rules and the tools you need to compare time anywhere. Choose What You Need Start with the tool that matches your question—convert time, detect your local zone, compare differences, browse abbreviations or plan a meeting across time zones. Time Zone Converter Convert times between zones and locations with date-aware rules. What Time Zone Am I In? Detect your IANA zone, current offset, abbreviation and seasonal status. Time Zone Chart Use a reference table for zones, abbreviations and UTC relationships. Time Zone Abbreviations Understand EST, EDT, CST, CET, IST and other time-zone codes. Time Zone Difference Compare the current difference between two zones or locations. Meeting Planner Find practical overlap for teams working across multiple time zones. U.S. Time Zones Now These live examples show the major continental U.S. time-zone families at the current moment. Seasonal abbreviations and UTC offsets update from the browser's time-zone data. World Time Zones Browse time zones by region, country and major location. Countries that span multiple time zones are shown with the zones and offsets that actually apply instead of being reduced to one national clock. UTC, GMT & Fixed Offsets UTC is the computational reference used to express time-zone offsets. GMT often displays the same clock time, but UTC and GMT are not identical concepts. Use fixed-offset pages when you need the live clock for a specific UTC±X or GMT±X offset. Current UTC Offset Examples A civil zone's current offset is date-aware. The examples below update automatically and include whole-hour, half-hour and 45-minute systems. Time Zone Names & Abbreviations Time-zone abbreviations are convenient, but some change seasonally and others can mean different things in different regions. Open the abbreviation you need for its current offset, meaning and related zone information. International Time-Zone Entities These guides cover common global abbreviations and live time-zone references, including seasonal standard and daylight variants. Standard Time vs Daylight Time Umbrella labels such as ET or PT can represent different seasonal forms. Fixed abbreviations such as EST and EDT have different UTC offsets and should not be used interchangeably. Quick Time Zone Compare Compare the current moment in two common zones. For a specific date and clock time, open the full Time Zone Converter. How Time Zones Work Four concepts explain most time-zone questions: UTC, offsets, civil zone rules and seasonal changes. Coordinated Universal Time is the reference used to express how far a local clock is ahead of or behind the global time standard.

Apply a UTC Offset An offset such as UTC−05:00 or UTC+05:30 describes the numerical difference between local time and UTC at a given moment. Use the Location's Zone An IANA identifier such as America/New_York carries location-based rules and transitions, so software can determine the correct offset for a requested date. Account for DST Some places change offset seasonally while others remain on the same offset all year. Rules differ by jurisdiction and can change through law. Separate ET from EST Umbrella names and fixed abbreviations are not always interchangeable. ET can mean EST or EDT depending on date and location. Expect Political Boundaries Time zones follow civil and administrative choices, not perfect 15-degree longitude strips. Countries and states can contain multiple zones or exceptions. IANA Time Zone vs UTC Offset They solve different problems. A UTC offset is a numeric value. An IANA time zone is a ruleset tied to representative locations and historical civil-time changes. Daylight Saving Time in the U.S. For 2026, U.S. daylight saving time is in effect from March 8 at 2:00 a.m. local time through November 1 at 2:00 a.m. local time where DST is observed. Not every U.S. jurisdiction observes DST. Hawaii, most of Arizona and several U.S. territories do not change clocks under the federal seasonal schedule. Prefer to See Time Zones on a Map? A map makes time-zone boundaries easier to understand at a glance. Explore the world map, U.S. map or a more detailed regional and state map when geography matters. Looking for the Current Time in a Place? Looking for the time in a specific place instead of its time zone? Use the World Clock and current-time pages for live local clocks, or stay here for time-zone names, UTC offsets, abbreviations and DST information. Popular Time-Zone References Popular Time-Zone Conversions Sources & Methodology CalendarHours uses location-aware, date-aware time-zone logic rather than permanently hardcoding civil offsets. IANA time-zone identifiers are used where a location's rules matter; fixed UTC/GMT offset pages are treated separately. The IANA Time Zone Database is the primary rules source for civil offsets, boundaries and transitions. The latest IANA release verified for this page is tzdb 2026c , released July 8, 2026. U.S. daylight-saving dates are checked against NIST, while U.S. time-zone oversight and boundary authority are referenced to the U.S. Department of Transportation. Reviewed August 18, 2026. This URL is evergreen; live clocks, abbreviations and current offsets update automatically from supported browser time-zone data. A time zone is a region that follows the same civil time rules. A time zone can be described by a UTC offset, but an offset alone is not a complete time zone because local rules can change with daylight saving time or legislation. There is no single universally useful count because “time zone” can mean a UTC offset, a named civil zone or an IANA identifier. In practical civil timekeeping there are more than 24 offsets because some locations use 30-minute or 45-minute differences and the International Date Line expands the range. The “Your Time Zone” panel above uses your browser's time-zone setting to show an IANA identifier, current UTC offset and local time. For a dedicated detector, use What Time Zone Am I In? A UTC offset is the amount of time a local clock is ahead of or behind Coordinated Universal Time. For example, UTC−05:00 is five hours behind UTC. A civil time zone's current offset can change when seasonal clock rules apply. No. A UTC offset is only a numerical difference from UTC. An IANA time zone such as America/New_York also represents rules and transitions that determine which offset applies on a given date. UTC is the modern global time standard used as the reference for time-zone offsets. GMT is a time reference and civil time-zone name. For ordinary clock reading they often show the same clock time, but they are not identical concepts. See GMT vs UTC . EST means Eastern Standard Time and is UTC−05:00. EDT means Eastern Daylight Time and is UTC−04:00. Eastern Time, or ET, is the umbrella term used when the current seasonal form depends on the date and location. No. Some civil time zones use half-hour or 45-minute offsets. India uses UTC+05:30 and Nepal uses UTC+05:45, for example. The time-zone identity usually stays the same, but the UTC offset or seasonal abbreviation can change when daylight saving or another seasonal rule is in effect. The applicable rule depends on location and date. An IANA time zone is an identifier such as America/New_York or Asia/Kolkata used by software to apply location-based civil time rules and historical transitions. The IANA Time Zone Database is updated when governments change time-zone boundaries, offsets or daylight-saving rules.