🌐 World Clock
See current time in major cities worldwide simultaneously.
What is this tool?
The World Clock tool shows the current time in major cities around the world, all displayed simultaneously in one view. Whether you are scheduling an international conference call, planning travel across time zones, or working with a distributed team, this tool helps you see what time it is everywhere at a glance. Time zones divide the Earth into regions that share the same standard time. There are 24 main time zones (one for each hour), though some regions use 30-minute or 45-minute offsets. UTC (Coordinated Universal Time) is the primary time standard, and all other time zones are defined as offsets from UTC. For example, New York is UTC-5 (or UTC-4 during daylight saving time), Tokyo is UTC+9, and Sydney is UTC+10 (or UTC+11 during their summer). This world clock displays the current time in over 20 major cities spanning all major time zones. It updates every second and accounts for daylight saving time automatically, so the displayed times are always accurate. You can quickly see which cities are in business hours, which are asleep, and find overlap windows for scheduling. Everything runs in your browser using your device's clock and the international time zone database.How it works
The tool uses JavaScript's Date object and the Intl.DateTimeFormat API to display times in different time zones. Each city is associated with an IANA time zone identifier (like "America/New_York" or "Asia/Tokyo"), which the browser uses to calculate the correct local time including daylight saving adjustments. The browser's time zone database (maintained by IANA) contains the rules for every time zone worldwide, including historical changes and daylight saving transitions. When the tool displays a time, it converts from your local time (or UTC) to the target city's time zone using these rules. Daylight saving time is handled automatically — when a region springs forward or falls back, the displayed time adjusts accordingly. The clock updates every second using a JavaScript timer. Each update re-reads the current time and recalculates the display for every city. The tool also shows whether each city is currently in daylight saving time (DST) with a small indicator, and whether it is day or night based on approximate sunrise/sunset times.How to use
- View the current time in major cities worldwide.
- Times update every second automatically.
- Look for the DST indicator where applicable.
- Use the times to find meeting windows across zones.
- Click any city to see more details.
Frequently Asked Questions
Frequently Asked Questions
How does daylight saving time work in the world clock?
The tool automatically accounts for daylight saving time (DST) using the IANA time zone database. When a city is currently observing DST, the time adjusts accordingly and a DST indicator is shown. Cities that do not observe DST (like most of Asia) never shift.
Why are some time zones 30 or 45 minutes off?
While most time zones are whole-hour offsets from UTC, some regions use 30-minute (like India at UTC+5:30) or 45-minute (like Nepal at UTC+5:45) offsets for geographic or political reasons. The world clock handles all these correctly.
How accurate is the world clock?
The clock is as accurate as your device's system clock, which typically syncs with internet time servers. The time zone calculations use the official IANA database, which is updated whenever governments change time zone rules.
Can I add custom cities?
The current version displays a curated list of major cities. However, you can use the Time Zone Finder tool to search for any specific time zone or city not shown in the world clock.
Tips & Advice
When scheduling across time zones, remember that the International Date Line means it can be different days in different locations — always double-check the date, not just the time, when planning international meetings. Business hours overlap is typically best between 9 AM and 5 PM in each location; for US-West to Europe, the overlap is narrow (morning US/afternoon Europe), while US-East to Asia has almost no comfortable overlap. Daylight saving time changes twice a year can shift meeting times unexpectedly — always reconfirm times after DST transitions. UTC is the safest reference point for international scheduling because it never changes. For recurring meetings, specify the time in UTC and let participants convert to their local zone.