Highlighted rows fall within 09:00–18:00 in both places: 3 shared working hours.
How many hours is CST behind GMT?
As abbreviations, GMT is always 6 hours ahead of CST: CST is UTC−6 and GMT is UTC+0. To convert, add 6 hours.
When the CST to GMT time difference changes
For most of the year GMT is 5 hours ahead of CST. From 1 November to 31 December 2026, GMT is 6 hours ahead of CST instead, because the two places change their clocks on different dates. Meetings booked by the usual gap land an hour off in those weeks.
Dates
GMT vs CST
Length
1 November 2026 to 31 December 2026
6 hours ahead
61 days
1 January 2027 to 13 March 2027
6 hours ahead
72 days
14 March 2027 to 6 November 2027
5 hours ahead
238 days
7 November 2027 to 31 December 2027
6 hours ahead
55 days
Best time for a meeting between CST and GMT
When GMT is 5 hours ahead of CST: 3 shared office hours, 09:00 to 12:00 in CST (14:00 to 17:00 in GMT).
When GMT is 6 hours ahead of CST: 2 shared office hours, 09:00 to 11:00 in CST (15:00 to 17:00 in GMT).
Frequently asked questions about CST and GMT time
How many hours ahead is GMT of CST?
GMT (UTC+0) is 6 hours ahead of CST (UTC−6).
Does the time difference between CST and GMT change?
Yes. It is usually 5 hours ahead, but changes when one side moves its clocks: 6 hours ahead from 1 November to 31 December 2026; 6 hours ahead from 1 January to 13 March 2027.