Timezone Calculator
About the Timezone Calculator
A demo scheduled for 3 PM Eastern is not 3 PM in Tokyo, and the offset between Sydney and San Francisco changes twice a year when daylight saving toggles on opposite hemispheres. Guessing cost meetings and missed flights long before video calls made the problem visible. This timezone calculator converts a specific date and time from one IANA time zone to another, applying offset rules-including DST-for that exact moment rather than a static GMT table printed years ago. Pick the instant, choose source and destination zones, and read the converted local time with offset context in the detail panel.
How to use it
- Enter the date and time as it is known in the source zone.
- Select From timezone-the region where that local time is correct.
- Select To timezone-the region you want to convert into.
- Click Convert timezone to see the destination local time.
- Copy the result into calendar invites, tickets, or chat.
- Re-run near DST change dates if planning far-ahead events.
Good to know
Results are calendar math from the dates you enter. Business-day tools skip weekends when they say so. They do not know local holidays unless the page says they do.
Frequently asked questions
Is the Timezone Calculator free?
Yes. You can use it in your browser with no account and no download.
Does the timezone calculator handle daylight saving?
Yes. Offsets are evaluated for the exact date-time you enter using IANA rules.
Why did the calendar date change after conversion?
Large offsets and the international date line can move an instant to the previous or next civil day.
How is this different from time-difference?
This converts one appointment between zones. Time-difference shows the current gap between two zones or two clock times.
Can I convert past historical times?
Yes. Enter the historical local time and zones; DST rules for that date apply.
Related
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