GMT to CDT Converter
Convert time between Greenwich Mean Time (GMT) and Central Daylight Time (CDT)
Greenwich Mean Time (GMT)
Central Daylight Time (CDT)
Time Difference
Central Daylight Time (CDT) is 0 hours ahead of Greenwich Mean Time (GMT)
Select Date
Select Time
Quick Reference
| GMT | CDT |
|---|---|
| 02:00 | 20:00 |
| 04:00 | 22:00 |
| 06:00 | 00:00 |
| 08:00 | 02:00 |
| 10:00 | 04:00 |
| 12:00 | 06:00 |
| 14:00 | 08:00 |
| 16:00 | 10:00 |
| 18:00 | 12:00 |
| 20:00 | 14:00 |
| 22:00 | 16:00 |
| 00:00 | 18:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
Related Time Zone Conversions
About GMT to CDT Time Conversion
Converting time from Greenwich Mean Time (GMT) to Central Daylight Time (CDT) is essential for UK to US Central region coordination. GMT is UTC+0, while CDT is UTC-5, making CDT 5 hours behind GMT.
This conversion is crucial for international business operations between the United Kingdom and the US Central region, including major business hubs in Texas, Illinois, and Missouri. Whether you're scheduling meetings, coordinating project deadlines, or planning travel, our accurate IANA-based converter ensures you never miss the time difference.
Common Use Cases for GMT to CDT Conversion
Business & Work
- Scheduling UK to US Central business meetings
- Coordinating London and Texas operations
- Managing international finance and trading across time zones
- Planning conference calls with distributed teams
Personal & Travel
- Planning travel from UK to US Central region (Texas, Illinois, Missouri)
- Coordinating with US Central family and friends from UK
- Scheduling virtual events and online meetings for UK-US Central audiences
- Arranging online classes or training sessions
Time Zone Information
Greenwich Mean Time (GMT)
- UTC Offset: UTC+0 (UTC+1 during BST)
- IANA Timezone: Europe/London
- Daylight Saving: Last Sunday in March to Last Sunday in October
- Major Cities: London, Edinburgh, Cardiff, Belfast, Dublin
- Coverage: United Kingdom and Ireland
Central Daylight Time (CDT)
- UTC Offset: UTC-5 (UTC-6 during CST)
- IANA Timezone: America/Chicago
- Daylight Saving: Second Sunday in March to First Sunday in November
- Major Cities: Chicago, Houston, Dallas, Austin, San Antonio, Memphis, Nashville
- Coverage: Central United States and Canada
Quick Reference: GMT to CDT
Remember: CDT is always 5 hours behind GMT. This conversion applies from second Sunday in March to first Sunday in November when CDT is active.
Frequently Asked Questions
What is the time difference between GMT and CDT?
Greenwich Mean Time (GMT) is UTC+0, while Central Daylight Time (CDT) is UTC-5. This means GMT is 5 hours ahead of CDT. When it's 12:00 PM (noon) in London (GMT), it's 7:00 AM in Chicago (CDT).
How does CDT differ from CST in terms of the GMT offset?
CDT (Central Daylight Time) is UTC-5, making it 5 hours behind GMT. CST (Central Standard Time) is UTC-6, making it 6 hours behind GMT. The difference between the two is 1 hour, with CDT being 1 hour ahead of CST. CDT is active from March to November, while CST is active from November to March.
Does the UK use GMT year-round?
No, the UK switches between GMT (UTC+0) in winter and BST (British Summer Time, UTC+1) in summer. BST is active from the last Sunday in March to the last Sunday in October. This means when the UK observes BST, the time difference to CDT becomes only 6 hours instead of 5.
When does CDT end and timezone transitions occur?
CDT ends on the first Sunday in November when Central Time transitions to CST. At the same time, the UK transitions from BST to GMT. This means the time difference between UK and US Central region changes from 6 hours (BST to CDT) to 6 hours (GMT to CST). The transitions happen on the same date but create different offsets.
What are the best times to schedule calls between UK and US Central?
Morning in the UK (8-10 AM GMT) overlaps with early evening in the US (3-5 PM CDT). Afternoon in the UK (2-4 PM GMT) overlaps with early morning in the US (9-11 AM CDT). For business operations, 2-4 PM UK time provides the most convenient overlap with US Central business hours.
Why is GMT to CDT conversion important?
GMT to CDT conversion is essential for coordinating between the United Kingdom and the US Central region, home to major business and tech hubs like Chicago, Dallas, and Austin. This conversion is vital for international business partnerships, financial operations, and personal communications between these major regions.
Pro Tips
- • The 5-hour difference means 12 PM in London equals 7 AM in Chicago - plan calls strategically to find good overlap times.
- • When GMT ends and CDT ends on the first Sunday of November, both regions transition simultaneously - GMT to CST and CDT to CST.
- • Schedule important UK-US Central meetings in early afternoon UK time (2-4 PM GMT, 9-11 AM CDT) to get the best overlap of working hours.
- • Remember that the UK will be on BST (6-hour difference) from late March to late October, not GMT (5-hour difference).
- • Use the 2-3 PM GMT window (9-10 AM CDT) for morning meetings on the US Central side while catching UK business hours.
- • For 24/7 operations with UK-US Central teams, split-shift scheduling is essential - UK afternoon/evening covers US morning, and vice versa.
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