GMT to CST Time Converter

Convert Greenwich Mean Time (GMT) to Central Standard Time (CST). Both time zones are shown live below; current offset between them is 6 hours behind.

London · Greenwich Mean Time
21:55:26
Sunday, May 10, 2026
GMT+1 · UTC+01:00
Chicago · Central Standard Time
15:55:26
Sunday, May 10, 2026
CDT · UTC-05:00

Convert a specific time

From: GMT (London)
To: CST (Chicago)
--:--

Daylight Saving status right now

GMT (Greenwich Mean Time)
Observes DST
Yes
In DST right now
Yes
Next fall back
2026-10-25
Offset shift
UTC+01:00 → UTC+00:00
CST (Central Standard Time)
Observes DST
Yes
In DST right now
Yes
Next fall back
2026-11-01
Offset shift
UTC-05:00 → UTC-06:00

When can GMT and CST meet?

00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
GMT
CST
Both zones in working hours (9am-5pm)
One zone working
Off-hours
Columns are hours of the day in London (GMT). Each row shows the local working-hours state in that zone for the same moment in time.
2 hours of overlap during standard 9am-5pm working hours.
Best meeting window: 15:00–16:00 GMT (09:00–10:00 CST).

Hour-by-hour GMT to CST conversion table

GMT time (London)CST time (Chicago)Status
00:00 Sun18:00 SatOff-hours both sides
01:00 Sun19:00 SatOff-hours both sides
02:00 Sun20:00 SatOff-hours both sides
03:00 Sun21:00 SatOff-hours both sides
04:00 Sun22:00 SatOff-hours both sides
05:00 Sun23:00 SatOff-hours both sides
06:00 Sun00:00 SunOff-hours both sides
07:00 Sun01:00 SunOff-hours both sides
08:00 Sun02:00 SunOff-hours both sides
09:00 Sun03:00 SunGMT working
10:00 Sun04:00 SunGMT working
11:00 Sun05:00 SunGMT working
12:00 Sun06:00 SunGMT working
13:00 Sun07:00 SunGMT working
14:00 Sun08:00 SunGMT working
15:00 Sun09:00 SunBoth at work
16:00 Sun10:00 SunBoth at work
17:00 Sun11:00 SunCST working
18:00 Sun12:00 SunCST working
19:00 Sun13:00 SunCST working
20:00 Sun14:00 SunCST working
21:00 Sun15:00 SunCST working
22:00 Sun16:00 SunCST working
23:00 Sun17:00 SunOff-hours both sides

Times computed for today in each zone using the IANA time zone database. The conversion accounts for daylight saving time wherever applicable.

About these time zones

Greenwich Mean Time (GMT)
IANA identifier
Europe/London
Current UTC offset
UTC+01:00
Current abbreviation
GMT+1
Major cities in this zone
LondonManchesterEdinburghBirmingham
Central Standard Time (CST)
IANA identifier
America/Chicago
Current UTC offset
UTC-05:00
Current abbreviation
CDT
Major cities in this zone
ChicagoHoustonDallasAustinNew Orleans

Sun today in London and Chicago

London
Sunrise
05:18
Sunset
20:38
Solar noon
12:58
Daylight
15h 20m
Chicago
Sunrise
05:37
Sunset
19:59
Solar noon
12:48
Daylight
14h 22m

Related converters

CST to GMT (reverse)GMT to ESTGMT to PSTGMT to UTCGMT to CETGMT to ISTEST to CSTPST to CSTUTC to CSTCET to CSTIST to CST
Looking for local time? See time in London or time in Chicago.

Frequently asked questions

What is the time difference between GMT and CST right now?+
CST (Central Standard Time) is currently 6 hours behind GMT (Greenwich Mean Time). The exact difference can change when one or both zones transition into or out of daylight saving time.
Does GMT or CST observe daylight saving time?+
GMT: observes daylight saving time. CST: observes daylight saving time.
When is the best time to schedule a meeting between GMT and CST?+
The strongest overlap is 15:00–16:00 GMT (09:00–10:00 CST), giving 2 hours when both sides are within standard 9am-5pm working hours.
What time is it in Chicago when it is 12:00 noon in London?+
When it is 12:00 Sun in London (GMT), it is 06:00 Sun in Chicago (CST).
Which IANA time zone identifiers are used for GMT and CST?+
GMT maps to "Europe/London" in the IANA database. CST maps to "America/Chicago". These identifiers are what most software libraries use to convert times accurately, including DST handling.
Is London ahead of or behind Chicago?+
Whether London (GMT) is ahead of or behind Chicago (CST) depends on the current UTC offsets. Right now CST is 6 hours behind GMT. The live converter and side-by-side clocks above always reflect the current direction.
What are the current UTC offsets for GMT and CST?+
GMT is UTC+01:00 (GMT+1) and CST is UTC-05:00 (CDT). Both offsets shift by one hour when the corresponding region enters or exits daylight saving time, so the live values on this page are the source of truth.
Can I schedule meetings during business hours for both GMT and CST?+
Yes. There are 2 hours of overlap during standard 9am-5pm working hours, with the strongest window at 15:00–16:00 GMT.