What is ART in MST?

Mountain Time is 4 hours behind

Argentina Time is on UTC−3:00 and Mountain Time is on UTC−7:00 right now. The gap changes during the year — see below.

Convert a time

ART — Argentina Time

MST — Mountain Time

1:00 am

MST, Sat

Time in Buenos Aires: 5:29:47 AM
Time in Denver: 1:29:47 AM
Difference: −4 h
Next clock change: March 14, 2027

When the difference changes

Argentina Time and Mountain Time do not change their clocks on the same dates, so the gap between them is not the same all year. Most converters show only today’s figure. These are the periods ahead:

Now – March 14, 2027Mountain Time is 4 hours behind
March 14, 2027 – November 7, 2027Mountain Time is 3 hours behind
November 7, 2027 – onwardsMountain Time is 4 hours behind

Periods shorter than a day are not listed. Each zone changes at its own local time, so on a date when both move there are a few hours when the gap is briefly something else.

Daylight saving

Argentina Time

No clock changes

Argentina Time stays on ART all year, so its offset from UTC never moves.

Mountain Time

Sunday, March 14, 2027

Clocks go forward one hour — 2:00 am becomes 3:00 am local time, and the zone is on MDT after that.

ART to MST conversion table

Every hour of Saturday, November 7, 2026, converted from Argentina Time to Mountain Time. 4 of the 24 hours fall on a different calendar day in Denver, which is marked.

12:00 am ART: 8:00 pm MST−1 day
1:00 am ART: 9:00 pm MST−1 day
2:00 am ART: 10:00 pm MST−1 day
3:00 am ART: 11:00 pm MST−1 day
4:00 am ART: 12:00 am MST
5:00 am ART: 1:00 am MST
6:00 am ART: 2:00 am MST
7:00 am ART: 3:00 am MST
8:00 am ART: 4:00 am MST
9:00 am ART: 5:00 am MST
10:00 am ART: 6:00 am MST
11:00 am ART: 7:00 am MST

12:00 pm ART: 8:00 am MST
1:00 pm ART: 9:00 am MST
2:00 pm ART: 10:00 am MST
3:00 pm ART: 11:00 am MST
4:00 pm ART: 12:00 pm MST
5:00 pm ART: 1:00 pm MST
6:00 pm ART: 2:00 pm MST
7:00 pm ART: 3:00 pm MST
8:00 pm ART: 4:00 pm MST
9:00 pm ART: 5:00 pm MST
10:00 pm ART: 6:00 pm MST
11:00 pm ART: 7:00 pm MST

Scheduling between the two

Working hours overlap from 1:00 pm to 6:00 pm ART, which is 9:00 am to 2:00 pm MST. Anything inside that window falls in the normal working day at both ends.

Mountain Time (MST) is used in Salt Lake City, Albuquerque and Calgary. Arizona keeps MST all year and does not follow MDT.