How many hours is London ahead of Chicago?

London is typically 6 hours ahead of Chicago. During US summer (CDT, UTC−5) and UK summer (BST, UTC+1), the gap is 6 hours. During US winter (CST, UTC−6) and UK winter (GMT, UTC+0), the gap is also 6 hours. The gap temporarily shifts to 5 hours during the brief windows when one side has transitioned to or from DST but the other has not.

What is the best meeting time for Chicago and London?

The sweet spot is 9 AM–noon CT, which corresponds to 3–6 PM GMT or BST in London. This window keeps Chicago participants in the morning and London participants in the afternoon. Avoid scheduling after 1 PM CT as that falls at or past 7 PM London time, which is outside most people’s preferred working hours.

When does the Chicago–London time gap change?

The gap changes briefly each spring and fall during the two-to-three-week window when only one country has transitioned to or from DST. The US and UK switch DST on different weekends. During these transitional periods, the gap narrows to 5 hours or widens to 7 hours temporarily before settling back to 6 hours.

Best Meeting Times Between Chicago and London

October 10, 2026

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Frequently Asked Questions

How many hours is London ahead of Chicago?: London is typically 6 hours ahead of Chicago. During US summer (CDT, UTC−5) and UK summer (BST, UTC+1), the gap is 6 hours. During US winter (CST, UTC−6) and UK winter (GMT, UTC+0), the gap is also 6 hours. The gap temporarily shifts to 5 hours during the brief windows when one side has transitioned to or from DST but the other has not.
What is the best meeting time for Chicago and London?: The sweet spot is 9 AM–noon CT, which corresponds to 3–6 PM GMT or BST in London. This window keeps Chicago participants in the morning and London participants in the afternoon. Avoid scheduling after 1 PM CT as that falls at or past 7 PM London time, which is outside most people’s preferred working hours.
When does the Chicago–London time gap change?: The gap changes briefly each spring and fall during the two-to-three-week window when only one country has transitioned to or from DST. The US and UK switch DST on different weekends. During these transitional periods, the gap narrows to 5 hours or widens to 7 hours temporarily before settling back to 6 hours.