Distributed teams use this tool when scheduling standup meetings. A team with members in New York, London, and Tokyo needs a time slot that falls within working hours for all three. The calculator scores each hour of the day based on how many participants are within their 9am to 5pm window.
Sales teams use it to schedule calls with international clients. A sales rep in San Francisco calling a client in Berlin needs to find a time that works for both. San Francisco is 9 hours behind Berlin, so 8am in San Francisco is 5pm in Berlin, which is the last hour of the German workday.
Event organizers use it for global webinars. If attendees join from Singapore, Dubai, London, and New York, the calculator shows which UTC hour gives the best coverage. A 2pm UTC slot puts Singapore at 10pm (outside hours), Dubai at 6pm (acceptable), London at 2pm (ideal), and New York at 9am (within hours).
Customer support managers use it to plan shift handoffs. A support team spanning Sydney, Mumbai, and London needs to identify overlap windows for handoff meetings. Sydney at 4pm, Mumbai at 11:30am, and London at 7am gives a workable window for all three.
The calculator checks every hour of the day in UTC and converts it to local time for each selected timezone. It then scores each hour based on how many participants are within their working hours. A score of 100 means all participants are within 9am to 5pm local time. A score of 75 means the slot is within 8am to 6pm. A score of 50 means 7am to 7pm. A score of 0 means the slot is outside reasonable hours for at least one participant.
The results are sorted by score, highest first. The top recommendation shows the UTC time, the score, and the local time for each participant with a color-coded indicator: green for within business hours, yellow for acceptable, red for outside preferred hours.
The tool uses IANA timezone identifiers (such as America/New_York and Asia/Tokyo) which automatically account for daylight saving time. This means the recommended meeting times remain accurate even when DST starts or ends in any of the selected regions.
Input
New York, London, Tokyo (1 hour meeting)
Output
14:00 UTC (Score: 67%)
New York 9am, London 2pm, Tokyo 11pm. Tokyo is outside business hours.
Input
New York, London, Mumbai (1 hour meeting)
Output
14:30 UTC (Score: 83%)
New York 9:30am, London 2:30pm, Mumbai 7pm. Mumbai is in acceptable hours.
Input
Los Angeles, London, Berlin (2 hour meeting)
Output
16:00 UTC (Score: 92%)
Los Angeles 8am, London 4pm, Berlin 5pm. All within or near business hours.
Input
Sydney, Dubai, London (1 hour meeting)
Output
07:00 UTC (Score: 75%)
Sydney 5pm, Dubai 11am, London 7am. London is early but acceptable.
Input
New York, Sao Paulo, London (1 hour meeting)
Output
15:00 UTC (Score: 92%)
New York 10am, Sao Paulo 12pm, London 3pm. All within business hours.
Things to watch out for
How does the scoring system work?
Each UTC hour is scored for each participant. If the local time falls within 9am to 5pm, that participant gets 100 points. Within 8am to 6pm gets 75. Within 7am to 7pm gets 50. Within 6am to 8pm gets 25. Outside those ranges gets 0. The overall score is the average across all participants.
Does the calculator account for daylight saving time?
Yes. The tool uses IANA timezone identifiers which include current DST rules. The UTC offsets shown reflect whether DST is currently active in each region. However, if you schedule a meeting for a date when DST status differs from today, the local times may shift by one hour.
What if there is no time slot that works for everyone?
For teams spread across more than 8 timezones, no slot will score 100%. The calculator still shows the best available option. Consider alternatives: rotate meeting times so the same person is not always inconvenienced, split into two regional meetings, or record the meeting for those who cannot attend live.
Can I customize the working hours?
The tool uses a fixed scoring window based on standard business hours (9am to 5pm for full score, 8am to 6pm for partial). You cannot customize the window, but you can use the ranked list to find slots that work for your team's specific schedule.
How many timezones can I compare at once?
You can select as many timezones as you need from the available list. The tool calculates scores across all selected zones. For very large teams, consider grouping nearby timezones together (for example, New York and Toronto are in the same timezone).
Why does the tool show UTC time as the recommendation?
UTC (Coordinated Universal Time) is the neutral reference point that does not observe daylight saving time. Sharing a UTC time avoids confusion because each participant converts it to their own local time. Calendar applications like Google Calendar and Outlook handle this conversion automatically when you send invites with timezone information.
What about regions with 30-minute or 45-minute offsets?
The tool handles fractional offsets correctly. India (UTC+5:30), Nepal (UTC+5:45), and parts of Australia (UTC+9:30) are all supported. The local time display shows the correct minutes for these regions.
UTC offsets reflect current daylight saving time status. If a meeting is scheduled for a future date when DST transitions occur, the local times shown may shift by one hour. Always verify meeting times close to the scheduled date, especially around March and November when most DST transitions happen.