Time Zone Converter & Date Calc
Convert a moment across time zones and compute date differences. Live clocks for 8 major zones (UTC, Shanghai, Tokyo, London…). Runs 100% in your browser.
Runs locally · data never uploaded
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How to use
What it does
Convert one instant across multiple zones and compute the gap between two dates, with live clocks for 8 major cities (UTC, Shanghai, Tokyo, London, Berlin, New York, Los Angeles, Sydney). It also reports the difference in days/hours/minutes plus business days.
Example
Pick "Shanghai" as the source zone and enter 2024-01-01 12:00 to see the matching local time in New York, London and more. For the date-difference panel, enter two dates to get something like "3 days 4 hours".
Notes
- Live clocks refresh every second
- The offset shown (e.g. +08:00) is the zone's difference from UTC
- Business days skip Saturday and Sunday
FAQ
Q1.Are the live clocks accurate?
They are based on your browser clock and refresh every second. If the OS clock is changed manually they will shift; otherwise they match standard time while online.
Q2.How is daylight saving time handled?
It uses the IANA time zone database (dayjs + Intl), so each region's DST rules are applied automatically — no manual toggle needed.
Q3.What are "business days" in the diff?
Business days are Monday through Friday, skipping Saturday and Sunday. If the start and end are the same day, the business-day count is 0.
Q4.Is my data uploaded?
No. All time math happens inside your browser.
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