Convert Central Daylight Time to Greenwich Mean Time
Instantly convert Central Daylight Time (CDT) to Greenwich Mean Time (GMT) with our free online calculator.
Central Daylight Time
12:20:56 AM
Wed, Jun 24 (CDT)
Greenwich Mean Time
05:20:56 AM
Wed, Jun 24 (GMT)
Convert a Specific Time
24-Hour Comparison
| CDT | GMT |
|---|---|
| 12:00 AM | 5:00 AM |
| 1:00 AM | 6:00 AM |
| 2:00 AM | 7:00 AM |
| 3:00 AM | 8:00 AM |
| 4:00 AM | 9:00 AM |
| 5:00 AM | 10:00 AM |
| 6:00 AM | 11:00 AM |
| 7:00 AM | 12:00 PM |
| 8:00 AM | 1:00 PM |
| 9:00 AM | 2:00 PM |
| 10:00 AM | 3:00 PM |
| 11:00 AM | 4:00 PM |
| 12:00 PM | 5:00 PM |
| 1:00 PM | 6:00 PM |
| 2:00 PM | 7:00 PM |
| 3:00 PM | 8:00 PM |
| 4:00 PM | 9:00 PM |
| 5:00 PM | 10:00 PM |
| 6:00 PM | 11:00 PM |
| 7:00 PM | 12:00 AM(+1d) |
| 8:00 PM | 1:00 AM(+1d) |
| 9:00 PM | 2:00 AM(+1d) |
| 10:00 PM | 3:00 AM(+1d) |
| 11:00 PM | 4:00 AM(+1d) |
How to Convert Central Daylight Time to Greenwich Mean Time
Formula
To convert Central Daylight Time (CDT) to Greenwich Mean Time (GMT): Convert CDT to GMT
About Central Daylight Time (CDT)
Central Daylight Time (CDT, IANA: America/Chicago during DST window) is the summer-time variant of CST, set at UTC-5:00 — observed from the second Sunday in March to the first Sunday in November per the US Energy Policy Act of 2005. CDT shares the same UTC offset as Eastern Standard Time (EST), so during winter months Chicago/Dallas are one hour behind New York/Atlanta, but during summer months Chicago/Dallas are still one hour behind because both regions advance equally for DST. The 'spring forward / fall back' transition affects an estimated 311 million US residents annually per Census data. CDT is used in 16 US states partially or fully (Illinois, Texas, Wisconsin, Minnesota, Iowa, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Tennessee, Kansas, Nebraska, Oklahoma, North Dakota, South Dakota) and parts of Canada (Manitoba, western Ontario, Saskatchewan partial — Saskatchewan stays on CST year-round, an exception). Affects MLB season game scheduling, CME / CBOT commodity trading hours, and US-Canada-Mexico USMCA cross-border supply-chain 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.