Chicago is currently 6 hours behind London. Convert time between Chicago and London, see the exact difference, and find the best hours for calls and meetings.
Chicago uses Central Daylight Time. London uses British Summer Time. Chicago time is 6 hours behind London. So, when it is 12:00 AM in Chicago, it is 6:00 AM in London.
Common Chicago times and their London equivalents.
| Chicago Time | London Time |
|---|---|
| 12:00 AM Chicago | 6:00 AM London |
| 1:00 AM Chicago | 7:00 AM London |
| 2:00 AM Chicago | 8:00 AM London |
| 3:00 AM Chicago | 9:00 AM London |
| 4:00 AM Chicago | 10:00 AM London |
| 5:00 AM Chicago | 11:00 AM London |
| 6:00 AM Chicago | 12:00 PM London |
| 7:00 AM Chicago | 1:00 PM London |
| 8:00 AM Chicago | 2:00 PM London |
| 9:00 AM Chicago | 3:00 PM London |
| 10:00 AM Chicago | 4:00 PM London |
| 11:00 AM Chicago | 5:00 PM London |
| 12:00 PM Chicago | 6:00 PM London |
| 1:00 PM Chicago | 7:00 PM London |
| 2:00 PM Chicago | 8:00 PM London |
| 3:00 PM Chicago | 9:00 PM London |
| 4:00 PM Chicago | 10:00 PM London |
| 5:00 PM Chicago | 11:00 PM London |
| 6:00 PM Chicago | 12:00 AM London |
| 7:00 PM Chicago | 1:00 AM London |
| 8:00 PM Chicago | 2:00 AM London |
| 9:00 PM Chicago | 3:00 AM London |
| 10:00 PM Chicago | 4:00 AM London |
| 11:00 PM Chicago | 5:00 AM London |
Chicago uses Central Time — Central Standard Time (CST, UTC−6) in winter and Central Daylight Time (CDT, UTC−5) in summer, shifting on the same US DST schedule. It sits one hour behind Eastern Time and two hours ahead of Pacific, placing it in the heart of US business scheduling overlap.
London uses Greenwich Mean Time (GMT, UTC+0) in winter and British Summer Time (BST, UTC+1) in summer. The UK clocks go forward one hour on the last Sunday of March and back on the last Sunday of October. GMT takes its name from the Royal Observatory in Greenwich, east London — the historical origin of UTC-based world time.
Both Chicago and London may observe Daylight Saving Time, which means the offset between them can change twice a year. Here is what to expect each season.
| Period | Note | Chicago | London | Offset |
|---|---|---|---|---|
| Nov – Mar | Both on standard time | CST (UTC−6) | GMT (UTC+0) | 6 hours |
| Mar – late Mar | US clocks forward, some zones still on standard | CDT (UTC−5) | GMT (UTC+0) | 5 hours |
| Late Mar – Oct current | Both on summer / daylight time | CDT (UTC−5) | GMT+1 (UTC+1) | 6 hours |
| Late Oct – early Nov | Clocks transitioning — check exact date | CST (UTC−6) | GMT (UTC+0) | 6 hours |
The transition window typically lasts 1–2 weeks in spring and autumn. If you have a recurring weekly meeting near a clock change, verify the exact date to avoid a missed call.
Chicago is currently 6 hours behind London. Chicago uses Central Daylight Time (UTC−5) and London uses British Summer Time (UTC+1).
The best overlap window is 9:00 am–12:00 pm Chicago time, which corresponds to 3:00 pm–6:00 pm London time. Both cities are within standard business hours (9 am–6 pm) during this window.
When it is 9:00 AM in Chicago, it is 3:00 pm in London. Chicago is 6 hours behind London.
When it is 5:00 PM in London, it is 11:00 am in Chicago.
Both Chicago and London observe Daylight Saving Time, but their transitions may not happen on the same date. During the brief 1–2 week windows in spring and autumn when only one zone has changed clocks, the offset between the two cities shifts by one hour. For most of the year the difference is 6 hours, but double-check the transition dates if you have a recurring meeting scheduled near those windows.