London to CDT
-6hLondon
BSTSOURCECDT
CDTGreen rows indicate typical business hours (9 AM - 5 PM)
BST and CDT on the World Map
The map below highlights the BST (Greenwich Mean Time) and CDT (Central Daylight Time) timezone regions across the globe.
GMT – Greenwich Mean Time
UTC+00:00Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.
- •GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
- •The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
- •GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
- •Iceland uses GMT year-round and never observes daylight saving time.
- •The UK switches from GMT to BST (British Summer Time) in late March each year.
CDT – Central Daylight Time
UTC-05:00Central Daylight Time (CDT) is the daylight saving offset in the Central Time Zone, 5 hours behind UTC.
- •CDT is the same offset as EST (UTC-05:00), which can cause confusion.
- •CDT runs from the second Sunday in March to the first Sunday in November.
About London
WikipediaLondon, where Greenwich Mean Time (GMT) originates, is the world's leading financial center alongside New York. The city bridges European and American business hours.
Big Ben is actually the name of the bell inside the Elizabeth Tower, not the tower itself.
Everything You Need to Know About London and CDT Time
London runs on British Summer Time (BST) at UTC+01:00, currently observing daylight saving time. CDT runs on Central Daylight Time (CDT) at UTC-05:00. That puts London 6 hours behind CDT — a difference of -6h at the current offsets.
In practice, when it is 9:00 AM in London it is 3:00 AM in CDT. Midnight in London is 6:00 PM in CDT.London observes daylight saving time while CDT does not, so the gap narrows or widens by an hour part of the year.
London to CDT time conversion table
| London (BST) | CDT (CDT) | Day |
|---|---|---|
| 12:00 AM | 6:00 PM | previous day |
| 6:00 AM | 12:00 AM | same day |
| 7:00 AM | 1:00 AM | same day |
| 8:00 AM | 2:00 AM | same day |
| 9:00 AM | 3:00 AM | same day |
| 12:00 PM | 6:00 AM | same day |
| 3:00 PM | 9:00 AM | same day |
| 5:00 PM | 11:00 AM | same day |
| 6:00 PM | 12:00 PM | same day |
| 9:00 PM | 3:00 PM | same day |
Why people convert London to CDT time
- Scheduling a call from London to CDT: a 10:00 AM start in London lands at 4:00 AM in CDT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both London and CDT are inside the 9-to-5 working day between 3:00 PM and 5:00 PM BST time (9:00 AM–11:00 AM CDT). That is roughly 2 hours of usable overlap.
- Watching a live event or market open: London viewers need 3:00 AM in CDT to catch a 9:00 AM start there, and 6:00 AM if the event is anchored to London.
- Always state the zone abbreviation, not just the hour. "3:00 PM BST" is unambiguous; "3 PM" across a -6h gap is not.
- Block 3:00 PM–5:00 PM BST as the recurring meeting window if you work primarily from London and need CDT colleagues present.
- London: Clocks fall back on Sun, Oct 25, 2026. Re-check this page after that date because the offset changes and so does the -6h gap.
About GMT (Greenwich Mean Time)
Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.
About CDT (Central Daylight Time)
Central Daylight Time (CDT) is observed during summer months in the US and Canadian portions of the Central Time Zone. Clocks are moved forward by one hour, aligning with Eastern Standard Time (EST). Most of Mexico and Central America do not observe CDT, staying on CST year-round.
Best time to call between London and CDT
Both London and CDT sit inside the 9 AM – 5 PM working day between 3:00 PM–5:00 PM BST, which is 9:00 AM–11:00 AM CDT. That gives roughly 2 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
London and CDT overlap for about 2 hours during the working day — enough for meetings if you avoid the edges of the window.
London is 6 hours behind CDT (BST UTC+01:00 → CDT UTC-05:00). The shared working window is 3:00 PM–5:00 PM BST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
London
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
CDT
☀ Currently in DST
Standard: UTC-06:00 · DST: UTC-05:00
Clocks fall back on Sun, Nov 1, 2026
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between London and CDT?
London (BST, UTC+01:00) is 6 hours behind CDT (CDT, UTC-05:00). The gap is currently -6h.
How do I convert London time to CDT time?
Add -6h to London local time. For example, 9:00 AM in London is 3:00 AM in CDT.
What time is it in CDT right now?
CDT uses CDT at UTC-05:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -6h offset from London.
What is the best time to call CDT from London?
Call between 3:00 PM and 5:00 PM BST — that maps to 9:00 AM–11:00 AM CDT and keeps both parties inside the working day.
Which is behind, London or CDT?
London is 6 hours behind CDT. When it is 12:00 PM in London it is 6:00 AM in CDT.
Do London and CDT use different time zones?
London (UK) uses BST at UTC+01:00, while CDT uses CDT at UTC-05:00. The IANA identifiers are Europe/London and America/Chicago.
Does daylight saving time affect the London–CDT difference?
Yes at the moment: London is on daylight saving time and CDT is not, so the -6h gap shifts by an hour when exactly one of them changes clocks.
Which other cities share London's time zone?
BST also covers London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar and 5 more.
Which countries use BST, London's zone?
BST is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, Mali, Mauritania and 7 more.
Is there a day difference between London and CDT?
Not normally. The -6h gap only pushes the date over the previous day.
What is the time difference between London and CDT?
CDT is -6h from London.
What timezone is London in?
London, where Greenwich Mean Time (GMT) originates, is the world's leading financial center alongside New York. The city bridges European and American business hours.
What timezone is CDT in?
CDT operates on its local timezone.
What are the business hours in London?
Standard business hours in London are 9:00 AM - 5:00 PM GMT.
Which countries use GMT (Greenwich Mean Time)?
GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, and 9 more countries.
Does GMT observe daylight saving time?
Yes, GMT switches to BST during summer months.
What are some interesting facts about GMT?
GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
Which cities are in the CDT timezone?
Major cities in the CDT timezone include Chicago, Houston, Dallas, Austin, Winnipeg, Nashville.
What is the UTC offset for CDT?
Central Daylight Time (CDT) is at UTC-05:00. During daylight saving time, it shifts to CST.
What should I know about the CDT timezone?
CDT is the same offset as EST (UTC-05:00), which can cause confusion. CDT runs from the second Sunday in March to the first Sunday in November.
When is it midnight in London, what time is it in CDT?
When it is 12:00 AM (midnight) in London (GMT), it is -6h later in CDT (CDT).
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