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Time Zone Converter

World Time Converter

Last reviewed: May 2026

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Time Zone Conversion

With remote work and global business, time zone conversion is an everyday need. This converter handles all 38 active time zones and accounts for Daylight Saving Time transitions automatically.[1] Enter a time in any zone and see the equivalent in any other. For scheduling meetings with multiple participants, the Meeting Time Planner finds the best overlap.

Major City Time Offsets (Standard Time)

CityUTC OffsetWhen NYC is 12 PM
Los AngelesUTC−89:00 AM
ChicagoUTC−611:00 AM
New YorkUTC−512:00 PM
LondonUTC+05:00 PM
Berlin/ParisUTC+16:00 PM
DubaiUTC+49:00 PM
MumbaiUTC+5:3010:30 PM
TokyoUTC+92:00 AM (+1 day)
SydneyUTC+103:00 AM (+1 day)

How Time Zones Work

Earth rotates 360 degrees in 24 hours, which means 15 degrees of longitude per hour. In theory, this would create 24 neat time zones each spanning 15 degrees. In practice, time zone boundaries follow political borders, economic relationships, and historical decisions rather than meridian lines. China spans five geographic time zones but uses a single time (UTC+8) nationwide, meaning sunrise in western China can occur as late as 10 AM local time. India uses a single half-hour offset (UTC+5:30) despite spanning 30 degrees of longitude. Russia uses 11 time zones across its vast territory, and Australia uses three main zones plus several half-hour variations.

The International Date Line runs roughly along the 180th meridian in the Pacific Ocean but deviates significantly to keep island nations on the same calendar day as their trading partners. Kiribati extends the date line eastward so its entire territory shares the same day, creating UTC+14, the farthest-ahead time zone on Earth. Samoa switched from the eastern to the western side of the date line in 2011, jumping forward by one day to align with Australia and New Zealand, its main trading partners, rather than the United States. For scheduling across time zones, see our Meeting Time Planner.

Daylight Saving Time Complications

Daylight Saving Time (DST) creates the most confusion in time zone conversions because not all countries observe it, and those that do change on different dates. The United States springs forward on the second Sunday in March and falls back on the first Sunday in November. The European Union changes on the last Sundays of March and October, creating several weeks where the US-Europe offset differs from its usual value. Australia's DST runs from October to April (Southern Hemisphere summer), meaning the offset between New York and Sydney changes four times per year as each region enters and exits DST independently.

RegionDST StatusStandard OffsetDST OffsetChange Dates
US EasternObservesUTC-5UTC-4Mar/Nov
UKObservesUTC+0UTC+1Mar/Oct
JapanDoes not observeUTC+9N/AN/A
IndiaDoes not observeUTC+5:30N/AN/A
Australia (Eastern)ObservesUTC+10UTC+11Oct/Apr
Arizona (US)Does not observeUTC-7N/AN/A

Time Zones for Remote Work and Global Teams

Remote work across time zones requires strategic scheduling to maintain team cohesion without burning out members in inconvenient zones. The concept of overlap hours, the window when all team members are available during reasonable working hours, determines meeting feasibility. A team spanning New York (UTC-5) to London (UTC+0) has a comfortable 4 to 5 hour overlap during standard business hours. A team spanning New York to Tokyo (UTC+9) has essentially zero overlap during normal hours, requiring either very early or very late meetings for one party.

Asynchronous communication tools (Slack, Loom, shared documents) reduce the need for synchronous overlap. The follow-the-sun model assigns work to team members in different zones so that progress continues around the clock, with handoff documents ensuring continuity. When synchronous meetings are necessary, rotating meeting times fairly across zones (rather than always placing the burden on one region) improves morale and retention. A Monday 9 AM EST standup can alternate weekly with 5 PM EST (10 PM London, 7 AM Tuesday Tokyo), distributing the inconvenience evenly. For calculating work hours and compensation across zones, see our Hourly to Salary Calculator and Deep Work Calculator.

Historical Development of Time Zones

Before standardized time zones, every city kept its own local solar time, meaning noon occurred when the sun was highest at each location. This created chaos for railroad scheduling because departure and arrival times in different cities used different clocks. In 1883, US and Canadian railroads adopted four standard time zones, and by 1884 the International Meridian Conference in Washington DC established the global system of 24 time zones centered on the Prime Meridian at Greenwich, England. Resistance was fierce: Detroit did not adopt Eastern Standard Time until 1900, and France refused to adopt the Greenwich-based system until 1911, calling their time "Paris Mean Time retarded by 9 minutes 21 seconds" rather than acknowledge Greenwich.

Unusual Time Zones and Edge Cases

Several time zones defy the standard whole-hour offset pattern. India uses UTC+5:30, Nepal uses UTC+5:45 (the only 45-minute offset in the world), and the Chatham Islands of New Zealand use UTC+12:45. Iran uses UTC+3:30, Afghanistan uses UTC+4:30, and Myanmar uses UTC+6:30. These fractional offsets exist for historical, geographic, or political reasons and create extra complexity for scheduling software and international communication.

Some regions have changed their time zones in recent decades for economic or political reasons. Samoa jumped forward across the International Date Line in 2011 to align with its major trading partners, skipping December 30 entirely. North Korea created its own Pyongyang Time at UTC+8:30 in 2015 and then reversed the change in 2018. Russia has repeatedly adjusted its time zones, reducing from 11 to 9 zones in 2010, then restoring 2 in 2014. Turkey permanently moved to summer time (UTC+3) in 2016, meaning its winter sunrise occurs as late as 8:30 AM in western cities. These changes highlight that time zones are political constructs rather than natural boundaries. For date-related calculations across regions, use our Date Calculator and Age Calculator.

Time zone awareness is critical for digital infrastructure. Servers typically run on UTC to avoid DST complications, and applications convert to local time only at the display layer. Database timestamps stored in local time create ambiguity during DST transitions: when clocks fall back, the hour from 1:00 to 2:00 AM occurs twice, making timestamps during that period genuinely ambiguous. The IANA Time Zone Database (often called the Olson database) maintains the authoritative record of all time zone rules and changes worldwide, and is updated multiple times per year as governments modify their time zone policies. Software that handles scheduling, logging, or international coordination should always use this database rather than hardcoded UTC offset values. For related date and time calculations, use our Unix Timestamp Converter and Week Number Calculator.

Coordinated Universal Time (UTC) replaced Greenwich Mean Time (GMT) as the world standard in 1972. While functionally identical for most purposes, UTC is maintained by a network of over 400 atomic clocks worldwide and is occasionally adjusted by leap seconds to stay synchronized with Earth's slightly irregular rotation. GPS satellites broadcast UTC, enabling precise time synchronization across the globe.

How many time zones are there?
There are 38 distinct time zones in use globally, ranging from UTC−12 to UTC+14. While most offset by whole hours, several use 30-minute (India at UTC+5:30) or 45-minute (Nepal at UTC+5:45) offsets. Some regions span multiple zones while others share one despite geographic spread.
What is the difference between UTC and GMT?
UTC (Coordinated Universal Time) and GMT (Greenwich Mean Time) are functionally the same for most purposes: they both refer to the time at the Prime Meridian (0° longitude). However, UTC is the modern scientific standard based on atomic clocks, while GMT is the traditional astronomical-based time. UTC does not observe daylight saving time.
How does Daylight Saving Time affect conversions?
DST shifts local time forward by 1 hour in spring and back in fall. Not all countries observe DST, and those that do change on different dates. This can temporarily change the offset between two cities. For example, New York is normally UTC−5 but becomes UTC−4 during DST (March-November).
What time zone does the International Date Line follow?
The International Date Line roughly follows the 180° meridian in the Pacific Ocean but zigzags to keep island nations on the same calendar day. Crossing it westward advances the date by one day; crossing eastward moves it back by one day. Samoa switched sides in 2011 to align with Australia and New Zealand.
How do I schedule meetings across time zones?
Find the overlap in business hours between all participants. For U.S. East Coast to London, the overlap is roughly 9 AM - 12 PM ET (2 PM - 5 PM London). For U.S. West Coast to Tokyo, there is very little overlap during normal hours, so early morning or late evening for one party is usually necessary.

How to Use This Calculator

  1. Select source time zone — Where you are or the origin time.
  2. Enter the time — In 12-hour or 24-hour format.
  3. Select target zone(s) — One or multiple destination time zones.

Tips and Best Practices

Account for DST. This converter adjusts automatically, but double-check near transition dates.[1]

Use UTC as a common reference. When coordinating across 3+ zones, express everything in UTC first.

Check date changes. Large offsets can cross the date boundary (today becomes tomorrow).[2]

For recurring meetings. The Meeting Time Planner finds optimal overlap across zones.

See also: Meeting Planner · Military Time · Hours Calculator · Countdown

📚 Sources & References
  1. [1] IANA. Time Zone Database. IANA.org
  2. [2] NIST. Time Zones. NIST.gov
  3. [3] timeanddate.com. World Clock. TimeAndDate.com
  4. [4] ISO 8601. Date and Time. ISO.org
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