This CST to GMT converter turns any time in Central Standard Time (CST) into Greenwich Mean Time (GMT), using your device clock so daylight saving is applied automatically. GMT is 6 hours ahead of CST when both zones are on standard time, and 5 hours ahead during the summer months when clocks have shifted. CST is UTC−6 (CDT: UTC−5); GMT is UTC+0.
CST covers Chicago, Dallas, Houston; GMT covers Accra, Dakar, London in winter. 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.
CST and GMT UTC offsets
CST
UTC−6
Central Standard Time
CDT UTC−5 from March 8 to November 1, 2026
GMT
UTC+0
Greenwich Mean Time
No daylight saving time
CST to GMT conversion table (standard time)
| CST | GMT |
|---|---|
| 12 am | 6 am |
| 3 am | 9 am |
| 6 am | 12 pm |
| 8 am | 2 pm |
| 9 am | 3 pm |
| 10 am | 4 pm |
| 11 am | 5 pm |
| 12 pm | 6 pm |
| 1 pm | 7 pm |
| 2 pm | 8 pm |
| 3 pm | 9 pm |
| 4 pm | 10 pm |
| 5 pm | 11 pm |
| 6 pm | 12 amnext day |
| 8 pm | 2 amnext day |
| 10 pm | 4 amnext day |
CST to GMT during daylight saving
Between the dates listed above, the difference is 5 hours instead of 6 hours.
| CST/CDT | GMT |
|---|---|
| 12 am | 5 am |
| 3 am | 8 am |
| 6 am | 11 am |
| 8 am | 1 pm |
| 9 am | 2 pm |
| 10 am | 3 pm |
| 11 am | 4 pm |
| 12 pm | 5 pm |
| 1 pm | 6 pm |
| 2 pm | 7 pm |
| 3 pm | 8 pm |
| 4 pm | 9 pm |
| 5 pm | 10 pm |
| 6 pm | 11 pm |
| 8 pm | 1 amnext day |
| 10 pm | 3 amnext day |
Frequently asked questions
What is the time difference between CST and GMT?
GMT is 6 hours ahead of CST on standard time. During daylight saving the gap changes to 5 hours. That comes from the UTC offsets: CST is UTC−6 and GMT is UTC+0. For example, 9 am CST = 3 pm GMT, and in summer 9 am CST = 2 pm GMT.
Is GMT ahead of or behind CST?
GMT is 6 hours ahead of CST, so when it is noon in CST it is 6 pm in GMT. Ahead means the clock there already shows a later time; a call at 5 pm CST lands at 11 pm GMT.
Does CST or GMT observe daylight saving time in 2026?
CST switches to CDT (UTC−5) on March 8 and back on November 1 in 2026. GMT keeps UTC+0 all year. 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 CST and GMT?
Standard office hours (9 am to 5 pm) overlap from 9 am to 11 am CST, which is 3 pm to 5 pm GMT. 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 CST and GMT?
CST (Central Standard Time) is used in Chicago, Dallas, Houston, Mexico City (no DST). GMT (Greenwich Mean Time) is used in Accra, Dakar, London in winter. 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.