How this works in your browser
Each city's time is derived from the current moment using your browser's built-in time zone database, the same IANA data operating systems use, rather than from stored offsets. That is what makes daylight saving handled automatically and correctly, including for regions that transition on different dates or do not observe it at all. Fractional offsets such as India's half hour and Nepal's forty-five minutes fall out of the same data without special handling. All ten clocks are recomputed each second from a single reference, so they stay exactly in step. Everything runs locally.
World Clock vs. typical online calculators
| Feature | World Clock (in-browser) | Typical online calculators |
|---|---|---|
| Where the maths runs | In your browser, on your device | Often posted to a server to compute |
| Your inputs are stored | Never - nothing is sent or saved | Frequently logged with your session |
| Works offline once loaded | Yes | No - needs a live connection |
| Ads inside the result area | None | Common on free calculators |
| Account required | No | Often, to save or export results |
| Usage limits | None - free, unlimited use | Sometimes capped per day |
Who uses World Clock
Scheduling across regions
Find an hour that is reasonable for everyone involved.
Working with distributed teams
See at a glance whether colleagues are likely to be at their desks.
Calling family abroad
Check it is not the middle of the night before dialling.
Following global markets or events
Track what time it is where something is happening.
How to use World Clock
- 1
Open the World Clock
Go to tools.slaytic.com and open the World Clock. No sign-up or account required.
- 2
Scan the cities
Ten major cities across the main time zones are shown together, updating live.
- 3
Check the dates too
Cities far apart can be on different calendar days, which matters when scheduling.
- 4
Find an overlapping window
Look for hours that are reasonable in every location you need.
Frequently asked questions
Does it account for daylight saving time?
Yes, times are calculated using each location’s current time zone rules, including daylight saving adjustments, via your browser’s built-in time zone database.
Can I add my own city?
This version shows a fixed set of major global cities. For a different city, check its time zone offset relative to one shown here.
How often does the time update?
Every second, for all cities simultaneously.
Why do some cities show a different date?
Because the world spans more than twenty-four hours of local time. When it is late evening in Los Angeles it is already the following afternoon in Sydney, so the date genuinely differs. This is the detail most often missed when scheduling, and it is why a meeting can land on a different day for one participant.
Why is India's time on a half hour?
Because time zone boundaries are political decisions rather than a strict consequence of geography. India uses a single offset half an hour from the whole-hour grid to serve a wide country with one national time. Nepal is thirty minutes further still, and several other regions use similar fractional offsets.
How does this help me schedule?
By showing whether an hour is reasonable rather than only what it is. A time that looks fine on paper may be six in the morning for someone, and seeing several cities together makes an overlapping window obvious in a way arithmetic does not.
Does it handle daylight saving?
Yes, automatically. Each city's time comes from your browser's time zone database, which tracks the current rules for every region, so the display is correct through daylight saving transitions without any adjustment.