World clock online: see current time in any city

Need to know what time it is right now in London, Tokyo, or New York? Use the free world clock on ToolHQ to see the current time in multiple cities simultaneously, updated in real time.

A world clock displays the current local time in any city or time zone you choose, live. Rather than mentally calculating time differences or searching for each city individually, you can add multiple locations and see them all on one screen.

For remote workers, international freelancers, and anyone who regularly communicates across borders, knowing the current time in multiple time zones is a daily need. The world clock removes the calculation step entirely. No mental math, no wrong assumptions about whether daylight saving has kicked in yet, just the correct local time for every city you care about.

Key Takeaways

• A world clock shows real-time local time in any city, updated every second
• UTC (Coordinated Universal Time) is the global reference; each time zone is UTC plus or minus some offset
• Daylight Saving Time shifts many time zones by one hour in spring and back in fall, and varies by country
• The IANA Time Zone Database is the standard reference used by computers worldwide to track time zone rules
• No data is stored or transmitted, the world clock runs entirely in your browser

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How time zones and world clocks work

Time is organized globally around UTC (Coordinated Universal Time), the primary time standard by which the world regulates clocks. According to Wikipedia's UTC article, UTC is the successor to Greenwich Mean Time (GMT) and is maintained by atomic clocks. Every time zone is expressed as an offset from UTC: UTC+0, UTC+5:30, UTC-8, and so on.

When you look at a world clock, you are seeing each city's local time calculated from UTC plus or minus its offset. New York is UTC-5 in winter (UTC-4 in summer). London is UTC+0 in winter (UTC+1 in summer). Tokyo is UTC+9 all year (Japan does not observe daylight saving time).

Time zone rules are maintained in the IANA Time Zone Database (also called tzdata), the authoritative reference for time zone and daylight saving rules used by operating systems, browsers, and databases worldwide. The database is updated whenever countries change their time zone rules, which happens more often than most people expect.

Daylight Saving Time

Daylight Saving Time (DST) shifts the clock forward by one hour in spring and back in fall in many countries, effectively changing a region's UTC offset seasonally. This is why a city that is "5 hours behind London" in January might only be "4 hours behind" in July.

Not all countries observe DST. Japan, China, India, and most countries near the equator do not. Within countries that do, the transition dates vary. The US moves clocks on the second Sunday in March; much of Europe does so on the last Sunday in March. This creates a brief window each spring and fall when the time difference between certain cities changes unexpectedly.

The world clock handles DST automatically. You always see the correct current local time without tracking seasonal transitions yourself.

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When you need a world clock

Scheduling calls and meetings across time zones. You are in Chicago and need to find a meeting time that works for colleagues in Berlin and Singapore. A world clock lets you look at all three cities at once, so you can identify the overlapping window during reasonable hours.

Working with international clients. A freelancer who works with clients in multiple countries needs to know when a 2 PM response email will actually be seen on the other end. If your London client is signing off for the day at 5:30 PM their time, you have a narrow window on a US East Coast morning.

Traveling across time zones. Before landing in a new time zone, you want to confirm what local time it is so you can plan whether to sleep or stay awake.

Remote team coordination. Distributed teams need a shared sense of where each person is in the day. A world clock provides that reference without calculation.

Take Daniel, an engineering manager at a company with teams in Austin, Amsterdam, and Bangalore. Every sprint kickoff required scheduling across those three cities. Amsterdam is UTC+1 in winter (UTC+2 in summer). Bangalore is UTC+5:30 all year. Austin is UTC-6 in winter (UTC-5 in summer). Without a world clock, he kept miscalculating the Amsterdam gap during DST transitions. He added all three cities to the world clock, bookmarked it, and opened it at the start of every scheduling conversation. The "Amsterdam window" for same-day overlap with Bangalore was small (roughly 9:30 AM Amsterdam to 1:30 PM Amsterdam), and seeing it live made scheduling those overlap sessions much faster.

Check the world clock now

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How to use the ToolHQ world clock

The world clock is instant and requires no setup.

1. Open the tool. The world clock shows the current time in real time as soon as it loads.
2. Add cities. Search for or select any city you want to track. The tool displays the current local time and UTC offset for each one.
3. Compare times. See all your selected cities side by side, updating every second.
4. Note DST status. The UTC offset shown for each city reflects DST if currently active, so you always see the accurate current offset.
5. Bookmark for quick access. Come back whenever you need to check across time zones.

No data is stored or transmitted. The clock runs entirely in your browser.

For converting a specific time from one city to another, the time zone converter is the dedicated tool. For counting down to a specific time in another time zone, the countdown timer works well once you know the equivalent time in your local zone.

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UTC offsets for popular cities

Standard UTC offsets (non-DST)

City	Country	Standard offset	DST offset	DST observed?
London	UK	UTC+0	UTC+1	Yes (Mar-Oct)
New York	USA	UTC-5	UTC-4	Yes (Mar-Nov)
Los Angeles	USA	UTC-8	UTC-7	Yes (Mar-Nov)
Chicago	USA	UTC-6	UTC-5	Yes (Mar-Nov)
São Paulo	Brazil	UTC-3	UTC-2	Yes (Oct-Feb)
Paris	France	UTC+1	UTC+2	Yes (Mar-Oct)
Berlin	Germany	UTC+1	UTC+2	Yes (Mar-Oct)
Dubai	UAE	UTC+4	UTC+4	No
Mumbai	India	UTC+5:30	UTC+5:30	No
Singapore	Singapore	UTC+8	UTC+8	No
Beijing	China	UTC+8	UTC+8	No
Tokyo	Japan	UTC+9	UTC+9	No
Sydney	Australia	UTC+10	UTC+11	Yes (Oct-Apr)
Auckland	New Zealand	UTC+12	UTC+13	Yes (Sep-Apr)

Note: DST dates vary and countries occasionally change their rules. Use the live world clock for the current accurate offset.

Why "GMT" and "UTC" are often used interchangeably

GMT (Greenwich Mean Time) refers to the mean solar time at the Royal Observatory in Greenwich, London. UTC replaced GMT as the international time standard in the 1960s and is based on atomic clocks rather than Earth's rotation. In everyday use, GMT and UTC are virtually identical, which is why both terms appear in time zone descriptions. The world clock operates on UTC.

Lena, a freelance translator, worked with four regular clients across Tokyo, Toronto, Warsaw, and Sydney. The challenge was not just knowing the time differences but knowing when each person was likely to be at their desk. She added all four cities to the world clock and saw immediately that there was no single hour in the day where all four cities were in working hours simultaneously. She used that insight to batch-schedule client communication: morning messages to Sydney before 9 AM her time, afternoon messages to Tokyo during her evening, and everything to Warsaw and Toronto during normal business hours. Her response turnaround improved because she stopped sending messages expecting same-day replies when the recipient was asleep.

The unix timestamp converter is useful when you need to convert times to and from epoch format for technical use, and the business days calculator helps when you need to count working days across a period that spans different time zones.

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Frequently asked questions

What is UTC and how does it relate to time zones?

UTC (Coordinated Universal Time) is the global time standard. Every time zone is expressed as UTC plus or minus an offset. New York is UTC-5 in standard time (UTC-4 during DST). Tokyo is UTC+9 all year.

Why does the time difference between two cities sometimes change?

Daylight Saving Time shifts clocks forward by one hour in spring and back in fall. Not all countries observe DST, and those that do change on different dates. During the "gap" around those transition dates, the difference between some city pairs changes by one hour.

Does the world clock update automatically for daylight saving time?

Yes. The world clock always shows the current local time, including any DST adjustment currently in effect. You do not need to track seasonal changes manually.

What is the IANA Time Zone Database?

The IANA Time Zone Database (tzdata) is the authoritative global reference for all time zone and DST rules. It is maintained by the Internet Assigned Numbers Authority and is used by operating systems, databases, and browsers to calculate correct local times worldwide.

Can I see the time in cities not on a default list?

Yes. ToolHQ's world clock lets you search for and add any city or time zone, not just a fixed preset list.

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The short version

A world clock removes the mental load of time zone arithmetic. You add the cities you care about, you see their current local times in real time, and DST is handled automatically. ToolHQ's world clock requires no account and no downloads.

For distributed teams, international clients, and travelers, a bookmarked world clock is one of the most practical browser tools you can have.

Open the free world clock now

For converting a specific time between two cities, use the time zone converter. For counting down to an event in another time zone, use the countdown timer. For Unix timestamp work in code, try the unix timestamp converter.

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