CST to GMT
+6hCST
CSTSOURCEGMT
GMTGreen rows indicate typical business hours (9 AM - 5 PM)
CST and GMT on the World Map
The map below highlights the CST (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.
Time Conversion Guide: CST to GMT
CST runs on Central Standard Time (CST) at UTC-06:00. GMT runs on Greenwich Mean Time (GMT) at UTC+00:00. That puts CST 6 hours ahead of GMT — a difference of +6h at the current offsets.
In practice, when it is 9:00 AM in CST it is 3:00 PM in GMT. Midnight in CST is 6:00 AM in GMT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
CST to GMT time conversion table
| CST (CST) | GMT (GMT) | Day |
|---|---|---|
| 12:00 AM | 6:00 AM | same day |
| 6:00 AM | 12:00 PM | same day |
| 7:00 AM | 1:00 PM | same day |
| 8:00 AM | 2:00 PM | same day |
| 9:00 AM | 3:00 PM | same day |
| 12:00 PM | 6:00 PM | same day |
| 3:00 PM | 9:00 PM | same day |
| 5:00 PM | 11:00 PM | same day |
| 6:00 PM | 12:00 AM | next day |
| 9:00 PM | 3:00 AM | next day |
Why people convert CST to GMT time
- Scheduling a call from CST to GMT: a 10:00 AM start in CST lands at 4:00 PM in GMT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both CST and GMT are inside the 9-to-5 working day between 9:00 AM and 11:00 AM CST time (3:00 PM–5:00 PM GMT). That is roughly 2 hours of usable overlap.
- Watching a live event or market open: CST viewers need 3:00 PM in GMT to catch a 9:00 AM start there, and 6:00 PM if the event is anchored to CST.
- Always state the zone abbreviation, not just the hour. "3:00 PM CST" is unambiguous; "3 PM" across a +6h gap is not.
- Block 9:00 AM–11:00 AM CST as the recurring meeting window if you work primarily from CST and need GMT colleagues present.
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 CST and GMT
Both CST and GMT sit inside the 9 AM – 5 PM working day between 9:00 AM–11:00 AM CST, which is 3:00 PM–5:00 PM GMT. That gives roughly 2 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
CST and GMT overlap for about 2 hours during the working day — enough for meetings if you avoid the edges of the window.
CST is 6 hours ahead of GMT (CST UTC-06:00 → GMT UTC+00:00). The shared working window is 9:00 AM–11:00 AM CST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
CST
☀ 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 CST and GMT?
CST (CST, UTC-06:00) is 6 hours ahead of GMT (GMT, UTC+00:00). The gap is currently +6h.
How do I convert CST time to GMT time?
Add +6h to CST local time. For example, 9:00 AM in CST is 3:00 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 +6h offset from CST.
What is the best time to call GMT from CST?
Call between 9:00 AM and 11:00 AM CST — that maps to 3:00 PM–5:00 PM GMT and keeps both parties inside the working day.
Which is ahead, CST or GMT?
CST is 6 hours ahead of GMT. When it is 12:00 PM in CST it is 6:00 PM in GMT.
Does daylight saving time affect the CST–GMT difference?
Neither zone observes daylight saving time, so the +6h offset between CST and GMT is fixed all year.
Which other cities share CST's time zone?
CST also covers Chicago, Houston, Dallas, San Antonio, Mexico City, Austin, Winnipeg, Memphis and 6 more.
Which countries use CST, CST's zone?
CST 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 CST and GMT?
Not normally. The +6h gap only pushes the date over for late-evening times.
What is the time difference between CST and GMT?
GMT is +6h from CST.
What timezone is CST in?
CST operates on its local timezone.
What timezone is GMT in?
GMT operates on its local timezone.
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 CST, what time is it in GMT?
When it is 12:00 AM (midnight) in CST (CST), it is +6h later in GMT (GMT).
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See every conversion from CST →·See every conversion from GMT →