OnSumoTools

Time Zone Meeting Planner

Map working hours across locations on one UTC grid and spot when everyone is free at once.

Meeting settings

Locations

Overlap grid (UTC hours)

Green = all locations in working hours. Amber = some overlap. Gray = off hours.

Location01234567891011121314151617181920212223
New York
19
20
21
22
23
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
London
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Overlap

Best meeting slots

  • UTC 14:00–18:00 (240 min)

    • New York: 9 AM – 1 PM
    • London: 2 PM – 6 PM

Offsets follow the IANA time zone database for your chosen date. Confirm the final time with attendees before you send invites.

How does the Time Zone Meeting Planner work step by step?

The tool maps each location's working hours to UTC for the reference date, then identifies UTC hours where all locations are simultaneously within their working windows.

What does a typical Time Zone Meeting Planner result look like?

Reference date: June 4, 2026 (both cities observing summer time)

Related tools

Frequently asked questions

  • How does the overlap grid work?

    Each row in the grid represents one location. Each column represents one UTC hour of the day (0-23). The cell color shows whether that location is within its configured working hours at that UTC time. Green columns are the hours where every location in your list is simultaneously in their working window. Those are your best meeting slots.

  • What about daylight saving time?

    The planner uses the IANA timezone database with your selected reference date to calculate exact offsets for every location on that specific day, including DST. A location's offset may shift by one hour between a winter and summer date. Always select the actual planned meeting date, not today's date, when the meeting is scheduled in advance.

  • What if there is no overlap?

    The tool shows \"No mutual business hours\" and displays which partial-overlap bands come closest. It identifies the earliest morning slot for one group and the latest evening slot for the other to help negotiate a mutually acceptable outside-hours time. No overlap is common between East Asian and North American teams regardless of business hours.

  • What should I do when the meeting must happen at a specific UTC time regardless of local hours?

    Enter the required UTC time and look at the grid to see what local time that corresponds to for each participant. The grid displays all 24 UTC hours and their local equivalents for each location, so you can read off exactly what time a given UTC hour lands in each participant's city. This is useful for scheduled maintenance windows, coordinated deployments, or any event driven by a fixed UTC timestamp rather than local business hours.

  • How do I account for a participant who is traveling and temporarily in a different time zone?

    Add a separate entry for that participant using their travel destination's timezone rather than their home location. You can label the row with their name and a note like \"(in Singapore this week)\" to avoid confusion. The tool treats each row as an independent location; it does not need to be a permanent address. Change the entry back to their home timezone after they return.

  • Why does the tool use IANA timezone names instead of UTC offsets?

    UTC offsets are ambiguous across the year because of daylight saving time. America/New_York is UTC-5 in winter and UTC-4 in summer; entering UTC-5 for a summer meeting would produce the wrong result. IANA timezone names encode the full historical and future DST transition rules for each location. Using the IANA name guarantees the correct offset for the specific reference date you enter, even for dates months in the future when DST transitions may have already occurred.

Finding a time that works for everyone

A team in San Francisco, London and Singapore has almost no shared working hours. Picking a meeting time by guessing offsets leads to someone joining at 3 a.m. and a lot of apologies.

Add up to eight locations and the planner draws a grid of the day for each one. The overlap shows where everyone is within normal working hours, so you can pick a time and copy it into your invite.

How the grid works

Each row is a city and each column is an hour in UTC. Green hours are inside the working window you set, say 9 to 17. Where the columns line up across all rows, that's your overlap. You can also set a meeting length, and the tool shows only blocks long enough to fit.

If there's no overlap at all, the tool says so. Then you have to choose who stretches. Rotate the burden so the same people don't always get the late call.

  • Rotate meeting times fairly between regions
  • Record the meeting and share notes for those who can't join
  • Prefer async updates when the overlap is thin

Daylight saving traps

Clocks change on different dates in different countries. The US and Europe shift weeks apart, and many places never change at all. For a few weeks each spring and autumn, the gap between two cities is an hour off from usual.

That's why the tool uses city names, which carry the correct rules, and not fixed offsets. The grid adjusts for the date you pick.

Special cases

If a call has to happen at a fixed UTC time, say so in the invite and list local times for each person. If someone is traveling, add their current city as an extra row. Always send the time with the zone, not just the clock.

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