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

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

CST to GMT Time Converter

Central Standard Time → Greenwich Mean Time

CST = UTC-5GMT = UTC+1

⚠️ CST is ambiguous — on this page it means Central Standard Time. It also refers to:

China Standard Time (Beijing) → GMT ↗Cuba Standard Time (Havana) → GMT ↗

ClockinSync

BASE

09:00

Work Clients Team +

00:0006:0012:0018:0024:00

GMT (London)

United Kingdom · +6h

15:00

New York

USA · +1h

10:00

Tokyo

Japan · +14h

23:00

Dubai

United Arab Emirates · +9h

18:00

Sydney

Australia · +15h

00:00+1 day

How far apart are CST (Chicago) and GMT (London)?

CST (Chicago) is 6 hours behind GMT (London). When CST (Chicago) clocks hit noon, GMT (London) reads 18:00.

CST (Chicago) is in the America/Chicago timezone. GMT (London) is in Europe/London. The difference is 6 hours.

Daily overlap window

Every working day, CST (Chicago) and GMT (London) are both in business hours for 2 hours simultaneously.

00:0006:0012:0018:0024:00

CST (Chicago)

GMT (London)

Overlap (2h)

When to schedule across time zones

Both CST (Chicago) and GMT (London) are in standard hours simultaneously for 2h per day.

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

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

Based on standard 09:00–17:00 working hours in each location's local time.

Holiday calendar for both locations

⚡ Both locations have upcoming holidays, check availability before scheduling.

CST (Chicago)7 holidays

Jul 3Independence DaySOON

Sep 7Labour Day

Oct 12Columbus Day

Oct 12Indigenous Peoples' Day

Nov 11Veterans Day

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

Working across CST (Chicago) and GMT (London)

Working across CST (Chicago) (USA) and GMT (London) (United Kingdom) involves a 6-hour gap. The good news: there is a 2-hour mutual window in standard business hours that lets both sides collaborate without anyone joining at an unreasonable hour.

💡 Best practice for cross-timezone meetings

✅

09:00–10:00 in CST (Chicago) = 15:00–16:00 in GMT (London). Both sides are in standard business hours during this window.

✅

10:00–11:00 in CST (Chicago) = 16:00–17:00 in GMT (London). Both sides are in standard business hours during this window.

DST transitions can silently shift your meeting times by an hour. The ClockinSync Chrome Extension tracks these changes automatically so you never get caught off guard.

Get the Extension — Free →

Use the time slider above to find the exact equivalent time for any moment in CST (Chicago). The input bar accepts natural language like "3pm", "15:30", or "9am Rome" for instant conversions.

CST (Chicago) ↔ GMT (London)

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

CST (Chicago)

GMT (London)

00:00

06:00

01:00

07:00

02:00

08:00