Time Zone Meeting Planner
Find the best meeting time across multiple time zones. See a visual grid of working hours for every participant and identify overlapping availability instantly.
Supports all IANA time zones with automatic Daylight Saving Time handling
Add Time Zones
Search and add time zones above to start comparing working hours.
How to Use This Meeting Planner
Add Time Zones
Search for cities or regions using the search box. Your local timezone is auto-detected. Add up to 10 time zones for comparison.
Read the Grid
Each row shows one timezone across 24 hours. Green cells are working hours (9 AM - 5 PM). Bright green columns mean all zones are available.
Pick a Meeting Time
Look for highlighted overlap columns or check the Best Meeting Windows section for a detailed breakdown of times in each zone.
How Time Zone Overlap Is Calculated
overlap = hours where ALL zones have 9:00 <= localHour < 17:00The planner uses the Intl.DateTimeFormat API to convert each UTC hour slot into the corresponding local time for every selected timezone. This ensures accuracy across all IANA zones including DST transitions.
For each UTC hour h (0-23):localHour[zone] = Intl.DateTimeFormat(zone).format(UTC_midnight + h * 3600s)isWorking[zone] = 9 <= localHour[zone] < 17overlap[h] = ALL zones have isWorking = trueKey details about the calculation:
- 24 UTC slots are generated starting from midnight UTC of the current day, covering a full day cycle
- Working hours are defined as 9:00 AM to 4:59 PM (17:00) in each local timezone, matching standard business hours
- DST is automatic because the browser Intl API resolves each timezone against the actual date, not a fixed UTC offset
- Overlap requires at least 2 zones since a single timezone trivially overlaps with itself
Frequently Asked Questions
How does the Time Zone Meeting Planner work?
Add the time zones of all meeting participants. The planner displays a 24-hour grid for each zone, color-coded to show working hours (9 AM to 5 PM in green). Columns where all participants are within working hours are highlighted as the best meeting windows.
What are working hours in this tool?
Working hours are defined as 9:00 AM to 5:00 PM (09:00-17:00) in each respective time zone. Hours within this range are shown in green, while hours outside are shown in gray. You can visually identify when all participants are available by looking for columns where every row is green.
Does this tool account for Daylight Saving Time?
Yes. The tool uses your browser's built-in Intl API which automatically handles Daylight Saving Time (DST) transitions. The times shown reflect the current DST status for each time zone, so you always see accurate local times.
How many time zones can I compare at once?
You can add up to 10 time zones simultaneously. This covers most international meeting scenarios. If you need to remove a zone, click the remove button next to its name. Your local time zone is automatically detected and added when you first load the page.
What if there is no overlapping working hours?
When participants span many time zones (for example, Australia and the US West Coast), there may be no overlap during standard 9-5 working hours. In that case, the tool will indicate that no overlap was found and you can visually scan the grid to find the least inconvenient time for all parties.
Note
This tool uses standard 9 AM to 5 PM working hours as a baseline. Actual working hours may vary by company, culture, and individual preference. Daylight Saving Time transitions are handled automatically by your browser, but always double-check critical meeting times close to DST change dates. Times shown reflect the current date.
Published by Kalcify · Last updated
Calculators are built against primary sources — government tax authorities (IRS, HMRC, CRA, ATO) for finance and the World Health Organization for health metrics. Updated when rates or rules change. View methodology and data sources.
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