Greenwich Mean Time (gmt) is used in United Kingdom. The IANA timezone identifier is Europe/London.

Central Daylight Time (cdt) is used in USA. The IANA timezone identifier is America/Chicago.

GMT to CDT Time Converter

Greenwich Mean Time → Central Daylight Time

GMT = UTC+1CDT = UTC-5

ClockinSync

BASE

09:00

Work Clients Team +

00:0006:0012:0018:0024:00

CDT (Chicago)

USA · -6h

03:00

New York

USA · -5h

04:00

Tokyo

Japan · +8h

17:00

Dubai

United Arab Emirates · +3h

12:00

Sydney

Australia · +9h

18:00

GMT (London) vs CDT (Chicago) — time difference

GMT (London) is 6 hours ahead of CDT (Chicago). At noon in GMT (London), your contact in CDT (Chicago) sees 06:00.

GMT (London) runs on Europe/London; CDT (Chicago) runs on America/Chicago. Together they are 6 hours apart.

Shared working hours

GMT (London) and CDT (Chicago) share 2 hours of overlapping business hours daily — enough for real-time collaboration without anyone joining at odd hours.

00:0006:0012:0018:0024:00

GMT (London)

CDT (Chicago)

Overlap (2h)

Best call times between these locations

There is a 2-hour daily window where both locations are in business hours.

15:00 London / 09:00 Chicago✓ Both working

16:00 London / 10:00 Chicago✓ Both working

Working hours defined as 09:00–17:00 local time for each location.

Public holidays for both locations

⚡ Holiday alerts for both locations, double-check schedules before confirming.

GMT (London)6 holidays

Jul 13Battle of the Boyne

Aug 3Summer Bank Holiday

Aug 31Summer Bank Holiday

Nov 30Saint Andrew's Day

Dec 25Christmas Day

CDT (Chicago)7 holidays

Jul 3Independence DaySOON

Sep 7Labour Day

Oct 12Columbus Day

Oct 12Indigenous Peoples' Day

Nov 11Veterans Day

Scheduling between GMT (London) and CDT (Chicago)

GMT (London) (United Kingdom) and CDT (Chicago) (USA) are 6 hours apart. With a 2-hour daily overlap in standard business hours, both teams can connect in real time without either side stretching beyond their normal workday.

💡 Scheduling tips for these locations

✅

If you are in GMT (London), aim for 15:00–16:00, which corresponds to 09:00–10:00 in CDT (Chicago) — both teams are within working hours.

✅

If you are in GMT (London), aim for 16:00–17:00, which corresponds to 10:00–11:00 in CDT (Chicago) — both teams are within working hours.

Avoid scheduling mistakes — especially around daylight saving changes. Use the ClockinSync Chrome Extension to instantly verify and compare both time zones directly in your browser, without manual calculations.

Add to your browser — Free →

Need a specific time? Use the slider or type directly into the input bar — it understands "3pm", "15:30", and location-specific formats like "9am GMT (London)".

GMT (London) ↔ CDT (Chicago)

2h of business hours overlap daily (09:00–17:00)

GMT (London)

CDT (Chicago)

00:00

18:00-1d

01:00

19:00-1d

02:00

20:00-1d

03:00

21:00-1d

04:00

22:00-1d

05:00

23:00-1d

06:00

00:00

07:00

01:00

08:00

02:00

09:00Working

03:00off

10:00Working

04:00off

11:00Working

05:00off

12:00Working

06:00off

13:00Working

07:00off

14:00Working

08:00off

15:00Working

09:00Working

16:00Working

10:00Working

17:00

11:00Working

18:00

12:00Working

19:00

13:00Working

20:00

14:00Working

21:00

15:00Working

22:00

16:00Working

23:00

17:00

Working hours: 09:00–17:00 local. Green = both working. Purple = one side only.

Frequently Asked Questions

What is the difference between gmt and cdt?

Greenwich Mean Time (gmt) is UTC+1 and Central Daylight Time (cdt) is UTC-5. The difference between them is 6 hours.

Where is gmt used?

Greenwich Mean Time (gmt) is used in United Kingdom and surrounding regions. The IANA timezone identifier is Europe/London.

Where is cdt used?

Central Daylight Time (cdt) is used in USA and surrounding regions. The IANA timezone identifier is America/Chicago.

How do I convert gmt to cdt?

Use the interactive converter above. Drag the time slider to any gmt time and the cdt equivalent updates instantly. You can also type a time like "3pm" or "15:00" in the input bar.

Popular GMT conversions

GMT → New York GMT → Tokyo GMT → Dubai GMT → Sydney GMT → Paris GMT → Berlin GMT → Singapore GMT → Los Angeles GMT → Toronto GMT → Mumbai

Popular CDT conversions

London → CDT New York → CDT Tokyo → CDT Dubai → CDT Sydney → CDT Paris → CDT Berlin → CDT Singapore → CDT Los Angeles → CDT Toronto → CDT