Chicago to London time converter
Enter a date and time in Chicago to see the matching time in London and the gap on that day. Useful for market hours and meetings between Chicago and London.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter date in chicago and time in chicago.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
The Chicago time (IANA America/Chicago) becomes UTC by subtracting its offset on that date, then the London offset (Europe/London) at the same instant is added: London time = Chicago time - Chicago UTC offset + London UTC offset.
Example
Inputs: Date in Chicago = 2026-07-15, Time in Chicago = 09:00. Result: Time in London: 15:00 Wednesday; Date in London: Wednesday, July 15, 2026 (2026-07-15); London vs Chicago: +6 hours.
Limits and caveats
- DST dates come from the device time-zone database, so a country rule change that your device has not received yet can shift the result.
- On a clock-change night in Chicago, a skipped or repeated local hour (such as 02:30 or 01:30) is read with one of the two offsets.
Questions about this tool
What is the time difference between Chicago and London?
London is 6 hours ahead of Chicago for most of the year because both use daylight saving time, but the gap drops to 5 hours for 2 to 3 weeks in March and 1 week around late October, since North America changes its clocks before the UK in spring and after it in autumn.
If it is 09:00 in Chicago, what time is it in London?
It is 15:00 in London for most of the year, and 14:00 in the weeks when the gap is 5 hours.
When is it already the next day in London?
From 18:00 in Chicago for most of the year, and from 19:00 when the gap is 5 hours, it is already the next day in London.