What this tool does
Convert a date and time between listed time zones, or compare work periods in 2–4 cities to find a meeting time that fits everyone.
How to use it
- Choose the source date, time and zone.
- Choose the destination zone and convert.
- Confirm the date as well as the clock time, especially around daylight-saving changes.
- For meeting planning, choose 2–4 cities and each local date and work period. Set the meeting length, find the overlap, and select a start before copying the dated times.
Method
The browser checks nearby time-zone offsets and converts each UTC candidate back to the entered local date and time. Only one exact match is accepted; skipped or repeated times are rejected. Intl.DateTimeFormat then formats the result using the browser’s time-zone data. Meeting planning converts each work-period boundary to an unambiguous UTC instant. The latest start and earliest end define shared availability. A meeting must fit wholly inside it; selectable starts move by one elapsed minute from the earliest start. Next-day endings advance the local calendar date, not the instant by a fixed 24 hours.
Worked example
On 2026-09-05, Seoul 09:00–18:00 and Kolkata 09:00–18:00 overlap from 03:30 to 09:00 UTC. A 60-minute meeting can start from 03:30 through 08:00 UTC. At the earliest start, Seoul reads 12:30–13:30 and Kolkata reads 09:00–10:00. When New York is on daylight time, 09:00 there commonly converts to 22:00 in Seoul on the same calendar date; in winter the difference is commonly 14 hours instead of 13. Use the selected date to get the applicable rule.
Common uses
- Scheduling international meetings
- Checking a travel arrival call
- Avoiding date mistakes across midnight
Limitations
Convert one time: Only the listed zones are available. Historical and future rule changes depend on the browser’s time-zone database. Skipped and repeated local times are blocked instead of silently choosing an instant. Choose another time or enter a confirmed UTC date and time with UTC as the source zone. Verify critical schedules with the organizer. Input and destination years must be AD 1–9999. Times are entered and displayed to the minute; historical second-level offsets are not shown. Find a meeting time: One-time planning only: no holidays, recurring schedules or calendar availability are checked. Meeting length is elapsed time; clock labels can jump or repeat at DST changes. Results include UTC offsets. Time-zone rules depend on your browser; confirm important meetings with participants. Meeting results include seconds and UTC offsets at both ends, including repeated clock labels. Work-period input uses years 0001–9999 and whole minutes.
FAQ
Does it use my current offset all year?
No. It converts the selected date with the browser’s rule for that zone, so seasonal offsets can differ.
Why did the destination date change?
The same instant can fall on the previous or next calendar day in another zone.