Chicago to GMT
+5hChicago
CDTSOURCEGMT
GMTGreen rows indicate typical business hours (9 AM - 5 PM)
CDT and GMT on the World Map
The map below highlights the CDT (Central Standard Time) and GMT (Greenwich Mean Time) timezone regions across the globe.
CST – Central Standard Time
UTC-06:00Central Standard Time (CST) is the time zone for the central United States, Canada, and Mexico, 6 hours behind UTC.
- •CST covers 20 US states fully or partially.
- •Chicago and Houston are the two largest cities in the Central Time Zone.
- •Mexico City, one of the world's most populous cities, operates on CST.
- •CST is 1 hour behind EST and 2 hours ahead of PST.
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.
About Chicago
WikipediaChicago operates on Central Time (CST/CDT), 1 hour behind New York. Home to CME and CBOE, Chicago is a global center for derivatives trading.
The Chicago Board of Trade is the world's oldest futures and options exchange.
Time Conversion Guide: Chicago to GMT
Chicago runs on Central Daylight Time (CDT) at UTC-05:00, currently observing daylight saving time. GMT runs on Greenwich Mean Time (GMT) at UTC+00:00. That puts Chicago 5 hours ahead of GMT — a difference of +5h at the current offsets.
In practice, when it is 9:00 AM in Chicago it is 2:00 PM in GMT. Midnight in Chicago is 5:00 AM in GMT.Chicago observes daylight saving time while GMT does not, so the gap narrows or widens by an hour part of the year.
Chicago to GMT time conversion table
| Chicago (CDT) | GMT (GMT) | Day |
|---|---|---|
| 12:00 AM | 5:00 AM | same day |
| 6:00 AM | 11:00 AM | same day |
| 7:00 AM | 12:00 PM | same day |
| 8:00 AM | 1:00 PM | same day |
| 9:00 AM | 2:00 PM | same day |
| 12:00 PM | 5:00 PM | same day |
| 3:00 PM | 8:00 PM | same day |
| 5:00 PM | 10:00 PM | same day |
| 6:00 PM | 11:00 PM | same day |
| 9:00 PM | 2:00 AM | next day |
Why people convert Chicago to GMT time
- Scheduling a call from Chicago to GMT: a 10:00 AM start in Chicago lands at 3:00 PM in GMT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Chicago and GMT are inside the 9-to-5 working day between 9:00 AM and 12:00 PM CDT time (2:00 PM–5:00 PM GMT). That is roughly 3 hours of usable overlap.
- Watching a live event or market open: Chicago viewers need 2:00 PM in GMT to catch a 9:00 AM start there, and 7:00 PM if the event is anchored to Chicago.
- Always state the zone abbreviation, not just the hour. "3:00 PM CDT" is unambiguous; "3 PM" across a +5h gap is not.
- Block 9:00 AM–12:00 PM CDT as the recurring meeting window if you work primarily from Chicago and need GMT colleagues present.
- Chicago: Clocks fall back on Sun, Nov 1, 2026. Re-check this page after that date because the offset changes and so does the +5h gap.
About CST (Central Standard Time)
Central Standard Time (CST) covers the central region of North America. It is the second most populous time zone in the US, including major cities like Chicago, Houston, and Dallas. CST is also used in Mexico City and much of Central America including Guatemala, Honduras, El Salvador, and Costa Rica. During summer, most of the US and Canada switch to Central Daylight Time (CDT, UTC-05:00), while Mexico and Central American countries generally remain on CST.
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.
Best time to call between Chicago and GMT
Both Chicago and GMT sit inside the 9 AM – 5 PM working day between 9:00 AM–12:00 PM CDT, which is 2:00 PM–5:00 PM GMT. That gives roughly 3 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
Chicago and GMT overlap for about 3 hours during the working day — enough for meetings if you avoid the edges of the window.
Chicago is 5 hours ahead of GMT (CDT UTC-05:00 → GMT UTC+00:00). The shared working window is 9:00 AM–12:00 PM CDT. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Chicago
☀ Currently in DST
Standard: UTC-06:00 · DST: UTC-05:00
Clocks fall back on Sun, Nov 1, 2026
GMT
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 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 Chicago and GMT?
Chicago (CDT, UTC-05:00) is 5 hours ahead of GMT (GMT, UTC+00:00). The gap is currently +5h.
How do I convert Chicago time to GMT time?
Add +5h to Chicago local time. For example, 9:00 AM in Chicago is 2:00 PM in GMT.
What time is it in GMT right now?
GMT uses GMT at UTC+00:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +5h offset from Chicago.
What is the best time to call GMT from Chicago?
Call between 9:00 AM and 12:00 PM CDT — that maps to 2:00 PM–5:00 PM GMT and keeps both parties inside the working day.
Which is ahead, Chicago or GMT?
Chicago is 5 hours ahead of GMT. When it is 12:00 PM in Chicago it is 5:00 PM in GMT.
Do Chicago and GMT use different time zones?
Chicago (USA) uses CDT at UTC-05:00, while GMT uses GMT at UTC+00:00. The IANA identifiers are America/Chicago and Europe/London.
Does daylight saving time affect the Chicago–GMT difference?
Yes at the moment: Chicago is on daylight saving time and GMT is not, so the +5h gap shifts by an hour when exactly one of them changes clocks.
Which other cities share Chicago's time zone?
CDT also covers Chicago, Houston, Dallas, San Antonio, Mexico City, Austin, Winnipeg, Memphis and 6 more.
Which countries use CDT, Chicago's zone?
CDT is used in United States (Central), Canada (Manitoba, Saskatchewan), Mexico, Guatemala, Honduras, El Salvador, Costa Rica, Nicaragua and 1 more.
Is there a day difference between Chicago and GMT?
Not normally. The +5h gap only pushes the date over for late-evening times.
What is the time difference between Chicago and GMT?
GMT is +5h from Chicago.
What timezone is Chicago in?
Chicago operates on Central Time (CST/CDT), 1 hour behind New York. Home to CME and CBOE, Chicago is a global center for derivatives trading.
What timezone is GMT in?
GMT operates on its local timezone.
What are the business hours in Chicago?
Standard business hours in Chicago are 8:00 AM - 5:00 PM CST.
Which countries use CST (Central Standard Time)?
CST is used in United States (Central), Canada (Manitoba, Saskatchewan), Mexico, Guatemala, Honduras, El Salvador, and 3 more countries.
Does CST observe daylight saving time?
Yes, CST switches to CDT during summer months.
What are some interesting facts about CST?
CST covers 20 US states fully or partially. Chicago and Houston are the two largest cities in the Central Time Zone.
Which cities are in the GMT timezone?
Major cities in the GMT timezone include London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar.
What is the UTC offset for GMT?
Greenwich Mean Time (GMT) is at UTC+00:00. During daylight saving time, it shifts to BST.
What should I know about the GMT timezone?
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.
When is it midnight in Chicago, what time is it in GMT?
When it is 12:00 AM (midnight) in Chicago (CST), it is +5h later in GMT (GMT).
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