Chicago to London Time Converter
London is 6 hours ahead of Chicago for most of the year. 9:00 AM in Chicago is 3:00 PM in London, or 2:00 PM in the 5-hour weeks.
One Hour Tighter Than New York
Chicago is on Central Time, one hour behind New York, so it is 6 hours behind London where New York is 5. London's 3:00 PM is 9:00 AM in Chicago and its 5:00 PM close is 11:00 AM, so the shared working window is only two hours, from 9:00 to 11:00 AM in Chicago.
London's 9:00 AM start is 3:00 AM in Chicago, well before anyone in Chicago is at a desk, so a London call has to come early in the Chicago morning.
The Two-Hour Overlap
Chicago's 9:00 to 11:00 AM is 3:00 PM to 5:00 PM in London on the usual 6-hour gap, inside both working days. After 11:00 AM in Chicago, London has already closed.
| Chicago | London |
|---|---|
| 9:00 AM–11:00 AM | 3:00 PM–5:00 PM |
| CST → GMT: Both inside 9 AM–5 PM Chicago's morning is London's late afternoon. | |
| 9:00 AM–12:00 PM | 2:00 PM–5:00 PM |
| CDT → GMT: Both inside 9 AM–5 PM In the 5-hour weeks the window is an hour longer. | |
"Inside 9 AM–5 PM" is a planning assumption for a standard office day on each side, not a claim about any company's hours.
When the Gap Is 5 Hours
| Stretch | Gap |
|---|---|
| Early January to second Sunday in March | 6 hours (CST and GMT) |
| Second Sunday to last Sunday in March (2 to 3 weeks) | 5 hours (Chicago on CDT, London still on GMT) |
| Last Sunday in March to last Sunday in October | 6 hours (CDT and BST) |
| Last Sunday in October to first Sunday in November (1 week) | 5 hours (London back on GMT, Chicago still on CDT) |
| First Sunday in November to end of year | 6 hours (CST and GMT) |
Chicago Hours Against the London Workday
The table lists each hour of the Chicago working day and the London time it lands on. A check mark means both cities are working. On CST only 9:00 and 10:00 AM in Chicago qualify (3:00 PM to 5:00 PM in London), because London closes at 5:00 PM. On the 5-hour gap a third hour opens.
| Chicago | London (CST → GMT) | London (CDT → BST) | London (CDT → GMT) |
|---|---|---|---|
| 8:00 AM | 2:00 PM | 2:00 PM | 1:00 PM |
| 9:00 AM | 3:00 PM ✓ | 3:00 PM ✓ | 2:00 PM ✓ |
| 10:00 AM | 4:00 PM ✓ | 4:00 PM ✓ | 3:00 PM ✓ |
| 11:00 AM | 5:00 PM | 5:00 PM | 4:00 PM ✓ |
| 12:00 PM | 6:00 PM | 6:00 PM | 5:00 PM |
| 1:00 PM | 7:00 PM | 7:00 PM | 6:00 PM |
| 2:00 PM | 8:00 PM | 8:00 PM | 7:00 PM |
| 3:00 PM | 9:00 PM | 9:00 PM | 8:00 PM |
| 4:00 PM | 10:00 PM | 10:00 PM | 9:00 PM |
| 5:00 PM | 11:00 PM | 11:00 PM | 10:00 PM |
| 6:00 PM | 12:00 AMnext day | 12:00 AMnext day | 11:00 PM |
Each row is an hour of the Chicago day. A check mark means both cities are inside a 9 AM to 5 PM working day at that moment.
- CST → GMT: 2 hours shared, 9:00 AM to 11:00 AM Chicago time.
- CDT → BST: 2 hours shared, 9:00 AM to 11:00 AM Chicago time.
- CDT → GMT: 3 hours shared, 9:00 AM to 12:00 PM Chicago time.
Chicago Hours in London Time
Full 24-hour reference table. Use the live clocks above for the exact current offset.
| 🇺🇸 CT | 🇬🇧 CST → GMTUTC-6 to UTC+0 | 🇬🇧 CDT → BSTUTC-5 to UTC+1 | 🇬🇧 CDT → GMTUTC-5 to UTC+0, a few weeks a year |
|---|---|---|---|
| 00:00 | 6:00 AM | 6:00 AM | 5:00 AM |
| 01:00 | 7:00 AM | 7:00 AM | 6:00 AM |
| 02:00 | 8:00 AM | 8:00 AM | 7:00 AM |
| 03:00 | 9:00 AM | 9:00 AM | 8:00 AM |
| 04:00 | 10:00 AM | 10:00 AM | 9:00 AM |
| 05:00 | 11:00 AM | 11:00 AM | 10:00 AM |
| 06:00 | 12:00 PM | 12:00 PM | 11:00 AM |
| 07:00 | 1:00 PM | 1:00 PM | 12:00 PM |
| 08:00 | 2:00 PM | 2:00 PM | 1:00 PM |
| 09:00 | 3:00 PM | 3:00 PM | 2:00 PM |
| 10:00 | 4:00 PM | 4:00 PM | 3:00 PM |
| 11:00 | 5:00 PM | 5:00 PM | 4:00 PM |
| 12:00 | 6:00 PM | 6:00 PM | 5:00 PM |
| 13:00 | 7:00 PM | 7:00 PM | 6:00 PM |
| 14:00 | 8:00 PM | 8:00 PM | 7:00 PM |
| 15:00 | 9:00 PM | 9:00 PM | 8:00 PM |
| 16:00 | 10:00 PM | 10:00 PM | 9:00 PM |
| 17:00 | 11:00 PM | 11:00 PM | 10:00 PM |
| 18:00 | 12:00 AMnext day | 12:00 AMnext day | 11:00 PM |
| 19:00 | 1:00 AMnext day | 1:00 AMnext day | 12:00 AMnext day |
| 20:00 | 2:00 AMnext day | 2:00 AMnext day | 1:00 AMnext day |
| 21:00 | 3:00 AMnext day | 3:00 AMnext day | 2:00 AMnext day |
| 22:00 | 4:00 AMnext day | 4:00 AMnext day | 3:00 AMnext day |
| 23:00 | 5:00 AMnext day | 5:00 AMnext day | 4:00 AMnext day |
* "next day" = converted time falls on the following calendar day.
A Chicago Early Start for a London Afternoon
If you're in Chicago and need London in its afternoon, you start early. An 8:00 AM Central start is 2:00 PM in London on the standard six hour gap, in winter and in summer alike. A 9:00 AM Chicago start is 3:00 PM.
London's 5:00 PM finish is 11:00 AM in Chicago. That puts the end of the London day in the middle of the Chicago morning, so an 11:00 AM start leaves London no time at all.
In the 5-hour weeks an 8:00 AM Chicago start is 1:00 PM in London, so check the date if your slot falls near either change.