What is a World Clock?
A World Clock is a tool that displays the current time across multiple timezones simultaneously. It allows you to see what time it is in different cities around the world at a glance, making it invaluable for scheduling meetings, coordinating teams across continents, or simply staying aware of the time in different parts of the world.
The traditional World Clock is a famous clock in Berlin, Germany that displays the current time in 24 cities around the world. Our digital version expands on this concept, allowing you to select from 40 preset cities and view real-time updates.
Understanding Timezones
The Earth is divided into 24 primary timezones, each roughly 15 degrees of longitude wide. Timezones are measured relative to UTC (Coordinated Universal Time), which is also called GMT (Greenwich Mean Time) when it refers to the timezone at 0 degrees longitude.
- UTC+X: Timezones east of the Prime Meridian and ahead of UTC
- UTC-X: Timezones west of the Prime Meridian and behind UTC
- UTC+0: The timezone at the Prime Meridian, including London in standard time
Some timezones use 30-minute or 45-minute offsets instead of whole hours. India Standard Time is UTC+5:30, and Nepal Standard Time is UTC+5:45.
Daylight Saving Time (DST)
Many countries and regions observe Daylight Saving Time (DST), also called Summer Time or Daylight Time. During DST, clocks are moved forward by one hour to make better use of evening sunlight during warmer months.
Typical DST Timeline
- Spring Forward: Usually the second Sunday of March in the US or the last Sunday of March in most of Europe
- Fall Back: Usually the first Sunday of November in the US or the last Sunday of October in most of Europe
Not all countries observe DST. China, India, Japan, and most African countries do not change their clocks. The Southern Hemisphere observes DST during opposite months, roughly September to April.
Major Timezones and Regions
A quick regional view helps you understand where common business, travel, and communication overlaps happen before you start comparing exact cities.
Americas
The Americas span from UTC-3:30 in Newfoundland to UTC-12 in parts of the Pacific. Major business timezones include Eastern, Central, Mountain, and Pacific time.
Europe and Africa
Europe commonly uses GMT or BST in the UK, CET or CEST in Central Europe, and EET or EEST in Eastern Europe. Much of Africa stays between UTC+1 and UTC+3 year-round.
Middle East and Asia
The Middle East often runs on UTC+3 or UTC+4. Asia includes several half-hour offsets, such as India at UTC+5:30, and stretches through UTC+9 in Japan and Korea.
Oceania
Australia spans multiple timezones and also has region-specific DST rules. New Zealand uses UTC+12 or UTC+13 depending on the season, while Hawaii stays on UTC-10 without DST.
How to Use the World Clock
Start with Quick Presets
- Pick a preset like Default Trio, Global Business, or US Major Cities.
- Use it as a starting layout instead of adding each city one by one.
- Replace the preset any time if your daily schedule changes.
Add and Reorder Cities
- Search for a city by name or country in the add selector.
- Click the result to add it to your clock board.
- Drag rows up or down to match the order you want on screen.
- Use the Set base control if you want a different city to drive comparisons.
Adjust the View and Compare Timezones
- Switch between 24-hour and 12-hour format depending on your preference.
- Pause live updates if you need a frozen view while planning.
- Turn on comparison mode in the comparison panel.
- Choose a base city from your selected clocks and pick any target city to compare.
- Use Copy All or Share to send the exact board state to someone else.
Timezone Offset Table
| Region | City | Standard Timezone | UTC Offset |
|---|---|---|---|
| Americas | New York | EST/EDT | UTC-5/-4 |
| Americas | Los Angeles | PST/PDT | UTC-8/-7 |
| Americas | Sao Paulo | BRT | UTC-3 |
| Europe | London | GMT/BST | UTC+0/+1 |
| Europe | Paris | CET/CEST | UTC+1/+2 |
| Europe | Kyiv | EET/EEST | UTC+2/+3 |
| Middle East | Dubai | GST | UTC+4 |
| Asia | Delhi | IST | UTC+5:30 |
| Asia | Bangkok | ICT | UTC+7 |
| Asia | Tokyo | JST | UTC+9 |
| Oceania | Sydney | AEST/AEDT | UTC+10/+11 |
| Oceania | Auckland | NZST/NZDT | UTC+12/+13 |
Common Use Cases
International Business
Schedule meetings across multiple time zones with remote teams, partners, and clients without doing manual offset math.
Travel Planning
Check local arrival times, understand overnight time jumps, and keep important city clocks visible before a trip.
Global Events
Coordinate launches, livestreams, webinars, or sports events that need a clear time reference for audiences in different regions.
Remote Teams
Keep a shared view of teammate locations so you can spot business-hour overlaps and avoid messaging someone in the middle of the night.
Frequently Asked Questions
Why do we have timezones?
Before timezones, each town kept its own local time based on the sun's position. When railroads and global communication became common, having a standard time system became necessary. Timezones allow coordinated communication while still matching local time to each region.
Is UTC the same as GMT?
For practical scheduling, UTC and GMT are effectively the same. UTC is the modern scientific standard, while GMT is the historical timezone label often used for UTC+0.
Does China use multiple timezones?
Geographically China spans several timezone widths, but the country officially uses one national timezone: China Standard Time at UTC+8.
Why do some timezones have 30 or 45-minute offsets?
Some governments chose offsets that better matched local geography, history, or national policy. That is why places such as India and Nepal use half-hour or quarter-hour offsets instead of whole hours.
When do I need to adjust my clock for DST?
DST changes happen on specific dates that vary by region. In the US, spring forward is usually on the second Sunday of March and fall back on the first Sunday of November. Europe typically changes on the last Sundays of March and October.