Time zone converter
Time and date
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About this tool
Convert local times in 13 IANA zones with explicit DST choices, then find common weekly working-hour meeting slots and prepare UTC ICS.
Common uses
- Resolve a repeated source time explicitly and compare its UTC/ISO/Unix instant.
- Find common working-hour candidates for colleagues without connecting their calendars.
How to use it
- 1.For conversion, enter source wall time, zones and an explicit earlier/later policy if it repeats.
- 2.For meetings, enter each person’s workdays and hours, a UTC search date and duration; find and inspect the shared windows.
- 3.Choose a start, review every local interval and offset plus the title and UTC stamp, then request ICS if needed.
Executed conversion and meeting examples
Shanghai to UTC
2026-01-05T09:00 Asia/Shanghai → UTC
2026-01-05T01:00:00.000Z
Explicit source zone; the browser host zone is irrelevant.
Shanghai and London working hours
2026-01-05 UTC; Shanghai09:00–18:00 + London09:00–18:00; Monday; 30minutes
09:00–10:00 UTC; 3
One shared UTC window09:00–10:00, three starts09:00/09:15/09:30. Names and local ranges appear in ICS.
New York repeated local time
2026-11-01T01:30 America/New_York; earlier / later
2026-11-01T05:30:00.000Z / 2026-11-01T06:30:00.000Z
Default reject requires a choice; spring gap2026-03-08T02:30 is always rejected.
Limits and notes
- 1–8 participants; 13 explicit IANA zones; UTC dates 2000–2099 and 1–7 days; 15-minute start grid. Every actual minute must fit every participant’s schedule. Adjacent local dates in 1999/2100 are allowed.
- Working intervals are [start, end), using 00:00–23:59. Equal start/end is rejected. Overnight shifts belong to the local weekday when the shift starts. Holidays and calendar appointments are not checked.
- Intl provides browser time-zone rules. Skipped local times have no instant; repeated times map to distinct UTC instants. Offsets may change inside a meeting. Future rules depend on the browser database.
- No uploads, storage, invitations or calendar permissions. ICS includes the meeting title, participant names, zones and local times: review before sharing.
- The earlier/later choice applies only to repeated wall times; skipped times are always rejected.
Frequently asked questions
Do slots mean everyone is free?
Find shared working time from your own weekly schedules. These are working-hour candidates, not personal calendar availability.
How are daylight-saving gaps and folds handled?
Intl provides browser time-zone rules. Skipped local times have no instant; repeated times map to distinct UTC instants. Offsets may change inside a meeting. Future rules depend on the browser database. The earlier/later choice applies only to repeated wall times; skipped times are always rejected.
What does the ICS contain?
No uploads, storage, invitations or calendar permissions. ICS includes the meeting title, participant names, zones and local times: review before sharing.