MST to CLT
+3hMST
MSTSOURCECLT
CLTGreen rows indicate typical business hours (9 AM - 5 PM)
MST and CLT on the World Map
The map below highlights the MST (Mountain Standard Time) and CLT (Chile Standard Time) timezone regions across the globe.
MST – Mountain Standard Time
UTC-07:00Mountain Standard Time (MST) is the time zone for the Mountain region of North America, 7 hours behind UTC.
- •Arizona does not observe daylight saving time, staying on MST year-round.
- •The Navajo Nation in Arizona does observe DST, unlike the rest of the state.
- •Denver, the 'Mile High City', is the largest city fully in MST.
- •MST covers 6 US states entirely and parts of several others.
CLT – Chile Standard Time
UTC-04:00Chile Standard Time (CLT) is the time zone for continental Chile, 4 hours behind UTC.
- •Chile observes daylight saving time, switching to CLST (UTC-03:00) in summer.
- •Santiago is the largest city in Chile with over 6 million in the metro area.
- •Chile spans over 4,300 km from north to south but uses one timezone.
Comparing Time Zones: MST and CLT
MST runs on Mountain Standard Time (MST) at UTC-07:00. CLT runs on Chile Standard Time (CLT) at UTC-04:00. That puts MST 3 hours ahead of CLT — a difference of +3h at the current offsets.
In practice, when it is 9:00 AM in MST it is 12:00 PM in CLT. Midnight in MST is 3:00 AM in CLT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
MST to CLT time conversion table
| MST (MST) | CLT (CLT) | Day |
|---|---|---|
| 12:00 AM | 3:00 AM | same day |
| 6:00 AM | 9:00 AM | same day |
| 7:00 AM | 10:00 AM | same day |
| 8:00 AM | 11:00 AM | same day |
| 9:00 AM | 12:00 PM | same day |
| 12:00 PM | 3:00 PM | same day |
| 3:00 PM | 6:00 PM | same day |
| 5:00 PM | 8:00 PM | same day |
| 6:00 PM | 9:00 PM | same day |
| 9:00 PM | 12:00 AM | next day |
Why people convert MST to CLT time
- Scheduling a call from MST to CLT: a 10:00 AM start in MST lands at 1:00 PM in CLT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both MST and CLT are inside the 9-to-5 working day between 9:00 AM and 2:00 PM MST time (12:00 PM–5:00 PM CLT). That is roughly 5 hours of usable overlap.
- Keeping family and friends in sync: knowing that 8:00 PM in MST is 11:00 PM in CLT makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM MST" is unambiguous; "3 PM" across a +3h gap is not.
- Block 9:00 AM–2:00 PM MST as the recurring meeting window if you work primarily from MST and need CLT colleagues present.
About MST (Mountain Standard Time)
Mountain Standard Time (MST) covers the Rocky Mountain region of the United States and Canada. Arizona is notable for not observing daylight saving time, staying on MST year-round (except the Navajo Nation). The time zone includes major cities like Denver, Phoenix, Calgary, and Salt Lake City. During summer, most areas switch to Mountain Daylight Time (MDT, UTC-06:00).
About CLT (Chile Standard Time)
Chile Standard Time (CLT) is the standard time in Chile. During summer months (October to March), Chile switches to Chile Summer Time (CLST, UTC-03:00). Chile is the longest north-south country in the world.
Best time to call between MST and CLT
Both MST and CLT sit inside the 9 AM – 5 PM working day between 9:00 AM–2:00 PM MST, which is 12:00 PM–5:00 PM CLT. That gives roughly 5 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
MST and CLT share 5 hours of working-hours overlap (9:00 AM–2:00 PM MST), so scheduling a live meeting is straightforward.
MST is 3 hours ahead of CLT (MST UTC-07:00 → CLT UTC-04:00). The shared working window is 9:00 AM–2:00 PM MST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
MST
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
Clocks fall back on Sun, Nov 1, 2026
CLT
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Apr 4, 2027
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 MST and CLT?
MST (MST, UTC-07:00) is 3 hours ahead of CLT (CLT, UTC-04:00). The gap is currently +3h.
How do I convert MST time to CLT time?
Add +3h to MST local time. For example, 9:00 AM in MST is 12:00 PM in CLT.
What time is it in CLT right now?
CLT uses CLT at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +3h offset from MST.
What is the best time to call CLT from MST?
Call between 9:00 AM and 2:00 PM MST — that maps to 12:00 PM–5:00 PM CLT and keeps both parties inside the working day.
Which is ahead, MST or CLT?
MST is 3 hours ahead of CLT. When it is 12:00 PM in MST it is 3:00 PM in CLT.
Does daylight saving time affect the MST–CLT difference?
Neither zone observes daylight saving time, so the +3h offset between MST and CLT is fixed all year.
Which other cities share MST's time zone?
MST also covers Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson and 2 more.
Which countries use MST, MST's zone?
MST is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).
Is there a day difference between MST and CLT?
Not normally. The +3h gap only pushes the date over for late-evening times.
What is the time difference between MST and CLT?
CLT is +3h from MST.
What timezone is MST in?
MST operates on its local timezone.
What timezone is CLT in?
CLT operates on its local timezone.
Which countries use MST (Mountain Standard Time)?
MST is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).
Does MST observe daylight saving time?
Yes, MST switches to MDT during summer months.
What are some interesting facts about MST?
Arizona does not observe daylight saving time, staying on MST year-round. The Navajo Nation in Arizona does observe DST, unlike the rest of the state.
Which cities are in the CLT timezone?
Major cities in the CLT timezone include Santiago, Valparaíso, Concepción, Viña del Mar, Antofagasta.
What is the UTC offset for CLT?
Chile Standard Time (CLT) is at UTC-04:00. During daylight saving time, it shifts to CLST.
What should I know about the CLT timezone?
Chile observes daylight saving time, switching to CLST (UTC-03:00) in summer. Santiago is the largest city in Chile with over 6 million in the metro area.
When is it midnight in MST, what time is it in CLT?
When it is 12:00 AM (midnight) in MST (MST), it is +3h later in CLT (CLT).
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See every conversion from MST →·See every conversion from CLT →