Time / Browser tools
World Clock
Follow live city clocks, compare offsets and find shared working hours with a shareable meeting strip and optional local storage.
World Clock: Add the cities you care about and see their current time side by side, with each city's offset from UTC, how far ahead or behind it is from you, and whether it is on daylight saving time. Times come from your browser's own time-zone database, so they follow every official clock change. Runs 100% locally in your browser with zero server file uploads.
- Category
- Time & calendar tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Choose up to 12 time zones. Cities sharing a zone use one clock.
Starting clocks…
Offsets use your browser’s IANA time-zone data. Intl has no DST flag: the higher seasonal offset is labelled DST. Political offset changes and negative-DST conventions can make that label ambiguous. Refresh after changing the device time zone.
Time-zone data
IANA zones describe local offset histories and rules. Browser database versions can differ, especially after recent rule changes. The site makes no time API requests. https://www.iana.org/time-zones
Intl.DateTimeFormat specification: https://tc39.es/ecma402/#datetimeformat-objects
Meeting overlap and DST
The strip covers 96 consecutive 15-minute intervals from the current quarter hour. Each interval must start and end within the configured local working window in every zone. Clock jumps follow real instants, so repeated and skipped local hours do not create fake time. DST status uses monthly samples and is an estimate; IANA cautions that standard/daylight distinctions can be complex: https://data.iana.org/time-zones/theory.html
How to use it
- Search city names or IANA zone identifiers and add up to 12 clocks.
- Set shared working hours and scan the next 24 hours in 15-minute intervals.
- Copy the sharing link or opt in to remember the city list on this device.
Privacy & limitations
Inputs stay in your browser. Nothing is uploaded.
Related tools
Frequently asked questions
Does the clock use a time service?
No. It uses the device clock and browser time-zone database. Its accuracy depends on both.
Why is DST labelled estimated?
The higher seasonal offset is treated as daylight time. Political changes, negative DST and unusual seasonal rules may make that label ambiguous. Numeric UTC offsets still come from Intl for the actual instant.
What is shared or saved?
The URL contains selected zones and working hours. City persistence is opt-in; turning it off removes the saved list. The planner uses the same hours daily, including weekends.
Free tool · runs in your browser · no account required