This GMT to CST converter turns any time in Greenwich Mean Time (GMT) into Central Standard Time (CST), using your device clock so daylight saving is applied automatically. CST is 6 hours behind GMT when both zones are on standard time, and 5 hours behind during the summer months when clocks have shifted. GMT is UTC+0; CST is UTC−6 (CDT: UTC−5).
GMT covers Accra, Dakar, London in winter; CST covers Chicago, Dallas, Houston. Because only CST observes daylight saving time, the difference is not constant through the year. The tables below show both cases, and the converter at the top always uses the rule in force on the date you pick.
GMT and CST UTC offsets
GMT
UTC+0
Greenwich Mean Time
No daylight saving time
CST
UTC−6
Central Standard Time
CDT UTC−5 from March 8 to November 1, 2026
GMT to CST conversion table (standard time)
| GMT | CST |
|---|---|
| 12 am | 6 pmprevious day |
| 3 am | 9 pmprevious day |
| 6 am | 12 am |
| 8 am | 2 am |
| 9 am | 3 am |
| 10 am | 4 am |
| 11 am | 5 am |
| 12 pm | 6 am |
| 1 pm | 7 am |
| 2 pm | 8 am |
| 3 pm | 9 am |
| 4 pm | 10 am |
| 5 pm | 11 am |
| 6 pm | 12 pm |
| 8 pm | 2 pm |
| 10 pm | 4 pm |
GMT to CST during daylight saving
Between the dates listed above, the difference is 5 hours instead of 6 hours.
| GMT | CST/CDT |
|---|---|
| 12 am | 7 pmprevious day |
| 3 am | 10 pmprevious day |
| 6 am | 1 am |
| 8 am | 3 am |
| 9 am | 4 am |
| 10 am | 5 am |
| 11 am | 6 am |
| 12 pm | 7 am |
| 1 pm | 8 am |
| 2 pm | 9 am |
| 3 pm | 10 am |
| 4 pm | 11 am |
| 5 pm | 12 pm |
| 6 pm | 1 pm |
| 8 pm | 3 pm |
| 10 pm | 5 pm |
Frequently asked questions
What is the time difference between GMT and CST?
CST is 6 hours behind GMT on standard time. During daylight saving the gap changes to 5 hours. That comes from the UTC offsets: GMT is UTC+0 and CST is UTC−6. For example, 9 am GMT = 3 am CST, and in summer 9 am GMT = 4 am CST.
Is CST ahead of or behind GMT?
CST is 6 hours behind GMT, so when it is noon in GMT it is 6 am in CST. Ahead means the clock there already shows a later time; a call at 5 pm GMT lands at 11 am CST.
Does GMT or CST observe daylight saving time in 2026?
GMT keeps UTC+0 all year. CST switches to CDT (UTC−5) on March 8 and back on November 1. Between those dates the difference in the table above shifts by an hour, which is the usual cause of missed calls in spring and autumn.
What is the best time for a meeting between GMT and CST?
Standard office hours (9 am to 5 pm) overlap from 3 pm to 5 pm GMT, which is 9 am to 11 am CST. Pick a slot inside that window and both sides stay within a normal working day. Check the daylight saving dates above, because the window moves by an hour when only one side has changed clocks.
Which cities use GMT and CST?
GMT (Greenwich Mean Time) is used in Accra, Dakar, London in winter. CST (Central Standard Time) is used in Chicago, Dallas, Houston, Mexico City (no DST). Note that the United Kingdom is only on GMT in winter; from late March to late October London runs on British Summer Time, one hour ahead, so use the BST pages for UK business hours in summer.