Free Time Zone Converter
Convert one date and time into every attendee's local time at once, and instantly see who is outside working hours.
What this does: converts a date and time from one time zone into as many other time zones as you add, using your browser's built-in Intl API. It flags night hours and times outside a 8 AM to 9 PM working window. No signup, no server upload: everything runs on your device.
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Frequently asked questions
How does this tool know my time zone?
It reads the time zone your browser already reports (the same one your operating system uses for its clock) and uses it as the default 'From' zone. You can change it at any time by searching for a different city or zone.
What does the 'Outside working hours' badge mean?
It flags any attendee whose converted local time falls before 8 AM or after 9 PM, so you can quickly spot a meeting time that would be inconvenient for someone before you send the invite.
Does this account for daylight saving time automatically?
Yes. Conversions use each region's official IANA time zone rules for the exact date you enter, so daylight saving changes are applied automatically and correctly for that date.