World Meeting Time Calculator
Choose a base city, meeting date, and time on the left, then add participant cities to compare their local times on the right and scan the 24-hour overlap timeline below.
Meeting setup
Participant cities 0
Choose a base city and meeting time to compare each city.
Local meeting times
Suggested times Most cities inside work hours
Calculations use your device’s IANA time-zone data through the browser Intl API, so daylight saving time follows the selected date. The weekday 9:00 AM–6:00 PM work window is only a scheduling aid; confirm holidays and each team’s actual hours before sending an invitation.
24-hour overlap timeline Base city, midnight through 11 PM
ready to use.
- Visible firstKeep the input and result positions clear.
- Results firstPut the main number up front and keep the process secondary.
- Less to askNo sign-up or extra information before using the tool.
Schedule one instant without losing a day or an hour
A meeting is one instant, but every participant reads it on a local clock and calendar. Choosing one base city first keeps the original date and time clear while the other cities update around it.
The calculator relies on IANA rules available in the device browser. Its work-hour colors narrow the search; they do not know a company calendar, public holiday, or a person’s actual availability.
Time-zone conversion starts with an instant, not a fixed hour difference
New York at 9:00 AM and London at 2:00 PM may describe the same instant, but the gap changes when their daylight-saving schedules are out of sync. A remembered “five-hour difference” is not enough for every date.
The engine resolves the base wall time first and then formats that instant in each IANA zone.
- Enter the meeting date as well as the time
- Use city zones instead of a fixed UTC offset
- Read the local calendar date with the clock time
Pick the base city that owns the original invitation
The base city is the clock you edit. Use the organizer’s office, the booked room, or the calendar in which the event was first created.
Reset returns the US view to New York with Los Angeles, London, and Tokyo as participants.
- Organizer in New York: use New York as base
- London-hosted webinar: use London as base
- Recheck the date after changing the base city
Add the city where each participant actually works
Country names are too broad for the United States, Canada, Australia, and other places with multiple time zones. Add each work location separately.
If several people share one zone, one representative city can cover them, but name the region in the invitation.
- Treat New York and Los Angeles separately
- Treat Sydney and Perth separately
- Remove cities that are no longer attending
Day-change badges prevent calendar mistakes
+1 day and -1 day compare the participant date with the base date. A late-afternoon US meeting can already be the next morning in Asia.
The badge matters most near midnight and around the International Date Line.
- Write the participant’s local date
- Include the weekday in the invitation
- Double-check Honolulu, Auckland, and Apia routes
Daylight saving time makes fixed offset charts stale
New York, London, Sydney, and many other cities change offset seasonally, and transition dates are not synchronized. The selected meeting date must drive the conversion.
IANA rules are updated when governments change civil time, while the browser receives those updates through the device software.
- Calculate the actual meeting date
- Keep the browser and operating system updated
- Verify policy changes with a local calendar
Work-hour colors are a common yardstick, not an availability promise
The green band means weekday 9:00 AM–6:00 PM; early or late covers 7:00–9:00 AM and 6:00–10:00 PM. Overnight covers the remaining hours.
That simple model does not include lunch, flexible schedules, holidays, or four-day workweeks.
- Use color to shortlist times
- Ask teams for their real core hours
- Check holidays before sending
Suggestions rank overlap; the timeline shows who bears the cost
Suggestion chips rank full hours by how many cities land inside the planning work window. The timeline exposes the entire day so you can see whether one team is repeatedly pushed into the night.
Clicking either control changes the base hour and updates every city result.
- Start with a suggestion when speed matters
- Use the full timeline to compare fairness
- Recheck dates after selecting an hour
Work through a New York, London, and Tokyo example
On a winter date, 9:00 AM in New York is typically 2:00 PM in London and 11:00 PM in Tokyo. During parts of the year, daylight-saving transitions change one of those relationships.
Use the actual date on screen rather than treating this example as a permanent offset table.
- Set New York as base and enter 9:00 AM
- Add London and Tokyo
- Read time, date badge, and color for each city
- Copy and compare with the calendar preview
Most invitation failures come from the wrong date or wrong city
Common mistakes include using a fixed offset through a DST change, choosing a country’s capital for a participant in another zone, and leaving the next-day date out of the invitation.
Saved cities are scoped to the language view. Reset a shared device before planning a different meeting.
- Do not reuse a fixed offset
- Choose the real work location
- Keep +1/-1 day in the shared text
- Reset stale participant lists
Keep the zone and a final calendar check in the invitation
A final invite should name the base time zone, show local dates and times, and include the conference link. Open the calendar preview after saving to confirm everyone points to one instant.
For interviews, broadcasts, launches, and deadlines, confirm with participants instead of relying on a single calculator result.
- Confirm base city and IANA zone
- Confirm every local date and weekday
- Use actual availability, not only the color band
- Review the saved calendar invitation
World meeting time calculator FAQ
How are meeting times converted across cities?
The entered wall time is resolved in the base city, then the same instant is formatted in every participant city.
Does the calculator account for daylight saving time?
Yes. It reads the selected date through browser IANA data, so seasonal offsets are applied automatically.
What do +1 day and -1 day mean?
They show that a participant city’s calendar date is one day ahead of or behind the base city.
Are the work-hour colors company-specific?
No. They use a shared weekday 9:00 AM–6:00 PM planning window and do not know holidays or team policies.
How are suggested times ranked?
Each base-city hour is scored by the number of cities inside the planning work window; up to three top hours appear.
Does it support half-hour and 45-minute offsets?
Yes. Zones such as India and Nepal retain their 30- and 45-minute offsets in city results.
What happens during a daylight-saving clock change?
The browser resolves the local wall time with its current time-zone data. For high-stakes meetings, confirm the invitation in each calendar.
Can I paste the result into an invitation?
Copy results produces localized dates, times, day differences, work-hour labels, and the final page URL.
Checked 2026-08-09. Calculations use the device IANA time-zone data exposed through Intl.DateTimeFormat.