Convert Central Standard Time to Greenwich Mean Time
Instantly convert Central Standard Time (CST) to Greenwich Mean Time (GMT) with our free online calculator.
Central Standard Time
11:20:55 PM
Tue, Jun 23 (CST)
Greenwich Mean Time
05:20:55 AM
Wed, Jun 24 (GMT)
Convert a Specific Time
24-Hour Comparison
| CST | GMT |
|---|---|
| 12:00 AM | 6:00 AM |
| 1:00 AM | 7:00 AM |
| 2:00 AM | 8:00 AM |
| 3:00 AM | 9:00 AM |
| 4:00 AM | 10:00 AM |
| 5:00 AM | 11:00 AM |
| 6:00 AM | 12:00 PM |
| 7:00 AM | 1:00 PM |
| 8:00 AM | 2:00 PM |
| 9:00 AM | 3:00 PM |
| 10:00 AM | 4:00 PM |
| 11:00 AM | 5:00 PM |
| 12:00 PM | 6:00 PM |
| 1:00 PM | 7:00 PM |
| 2:00 PM | 8:00 PM |
| 3:00 PM | 9:00 PM |
| 4:00 PM | 10:00 PM |
| 5:00 PM | 11:00 PM |
| 6:00 PM | 12:00 AM(+1d) |
| 7:00 PM | 1:00 AM(+1d) |
| 8:00 PM | 2:00 AM(+1d) |
| 9:00 PM | 3:00 AM(+1d) |
| 10:00 PM | 4:00 AM(+1d) |
| 11:00 PM | 5:00 AM(+1d) |
How to Convert Central Standard Time to Greenwich Mean Time
Formula
To convert Central Standard Time (CST) to Greenwich Mean Time (GMT): Convert CST to GMT
About Central Standard Time (CST)
Central Standard Time (CST, IANA: America/Chicago, America/Mexico_City) is the time zone for the US Central region, central Mexico, and most of Central America, set at UTC-6:00. CST is the most populous US time zone by area covered and serves the Chicago-Dallas-Houston-Minneapolis corridor of ~80 million people across CST states (Texas, Illinois, Wisconsin, Minnesota, Iowa, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Tennessee western, Kansas eastern, Nebraska eastern, Oklahoma, North Dakota, South Dakota, Kentucky western, Indiana western, Michigan UP, Florida panhandle) plus Mexico (Mexico City, Guadalajara, Monterrey since 2022 DST abolition), Honduras, Nicaragua, El Salvador, Costa Rica, Guatemala, Belize. CST observes DST (switching to CDT = UTC-5:00) per Energy Policy Act 2005 — except for Mexico nationally, which abolished DST in 2022 except for border zones aligning with US DST. CST affects: NYSE close at 15:00 CST, CME (Chicago Mercantile Exchange) commodity futures pit/electronic hours, Texas Medical Center coordinated patient handoffs.
About Greenwich Mean Time (GMT)
Greenwich Mean Time (GMT, IANA: Europe/London) is the historic and current civil time of the United Kingdom (during winter), Ireland (during winter), Portugal mainland (during winter), Iceland (year-round), and most West African countries. GMT is set at UTC+0 — the time on the Prime Meridian (0° longitude) running through the Royal Observatory in Greenwich, southeast London. Established as the global time reference by the 1884 International Meridian Conference in Washington DC, GMT served as the world's primary civil-time reference from 1884 until 1972 when UTC (Coordinated Universal Time) was adopted as the new precision standard. The UK switches from GMT to British Summer Time (BST = UTC+1) at 01:00 GMT on the last Sunday of March and back to GMT at 02:00 BST on the last Sunday of October per EU Directive 2000/84/EC (UK retained this schedule after Brexit). GMT affects: London Stock Exchange (LSE) trading hours, BBC World Service broadcast time-stamps, all aviation NOTAMs and weather METARs which use UTC = GMT, and ICAO + IMO worldwide maritime/aviation coordination.