Offset
The time difference between Mountain Time and Argentina Time is 3 hours.
Mountain Time (MDT) is behind Argentina Time (ART).
MDT: UTC-6
ART: UTC-3
Mountain Time is currently observing daylight saving time; Argentina Time is not.
When to schedule
Business-hours overlap: 9 AM–2 PM in Mountain Time (12 PM–5 PM in Argentina Time).
Both teams are in working hours during this window on weekdays.
Suggested time: 11:00 AM Mountain Time (2:00 PM Argentina Time).
This window may shift by an hour during daylight saving time.
Public holidays in 2026
National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.
United States
- New Year's DayThu, Jan 1
- Martin Luther King, Jr. DayMon, Jan 19
- Presidents DayMon, Feb 16
- Memorial DayMon, May 25
- Juneteenth National Independence DayFri, Jun 19
- Independence DayFri, Jul 3
- Labour DayMon, Sep 7
- Columbus DayMon, Oct 12
- Veterans DayWed, Nov 11
- Thanksgiving DayThu, Nov 26
- Christmas DayFri, Dec 25
Argentina
- New Year's DayThu, Jan 1
- CarnivalMon, Feb 16
- CarnivalTue, Feb 17
- Day of Remembrance for Truth and JusticeTue, Mar 24
- Day of the Veterans and Fallen of the Malvinas WarThu, Apr 2
- Good FridayFri, Apr 3
- Labour DayFri, May 1
- May RevolutionMon, May 25
- Anniversary of the Passing of General Martín Miguel de GüemesMon, Jun 15
- General Manuel Belgrano Memorial DaySat, Jun 20
- Independence DayThu, Jul 9
- General José de San Martín Memorial DayMon, Aug 17
- Day of Respect for Cultural DiversityMon, Oct 12
- National Sovereignty DayMon, Nov 23
- Immaculate Conception DayTue, Dec 8
- Christmas DayFri, Dec 25
About these zones
Mountain Time is also known as MST, or MDT. To call United States, dial +1.
Argentina Time is also known as ART. To call Argentina, dial +54.
Argentina Time is approximately 5,950 miles southeast of Mountain Time.
Quick reference
Full 24-hour conversion table — tap any time to open it in the converter.
| MST | ART | Day |
|---|---|---|
| 12:00 am | 3:00 am | Same day |
| 1:00 am | 4:00 am | Same day |
| 2:00 am | 5:00 am | Same day |
| 3:00 am | 6:00 am | Same day |
| 4:00 am | 7:00 am | Same day |
| 5:00 am | 8:00 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 |
| 10:00 am | 1:00 pm | Same day |
| 11:00 am | 2:00 pm | Same day |
| 12:00 pm | 3:00 pm | Same day |
| 1:00 pm | 4:00 pm | Same day |
| 2:00 pm | 5:00 pm | Same day |
| 3:00 pm | 6:00 pm | Same day |
| 4:00 pm | 7:00 pm | Same day |
| 5:00 pm | 8:00 pm | Same day |
| 6:00 pm | 9:00 pm | Same day |
| 7:00 pm | 10:00 pm | Same day |
| 8:00 pm | 11:00 pm | Same day |
| 9:00 pm | 12:00 am | +1 day |
| 10:00 pm | 1:00 am | +1 day |
| 11:00 pm | 2:00 am | +1 day |
Daylight saving time
Mountain Time observes daylight saving time; Argentina Time does not. The offset between the two zones changes when Mountain Time transitions: on Sunday, November 1, 2026, clocks fall back from MDT to MST.
See the daylight saving time page for transition dates across every time zone.
Daylight today
- Sunrise
- 5:34 AM
- Sunset
- 8:25 PM
- Day length
- 14h 51m
- Sunrise
- 7:55 AM
- Sunset
- 5:51 PM
- Day length
- 9h 56m
Cities in these zones
Cities in Mountain Time
Cities in Argentina Time
Browse all cities to see the current local time anywhere.
Airports in these zones
Airports in Mountain Time
- BJC
- DEN
- OGD
- SLC
Airports in Argentina Time
- AEP
- EZE
Related conversions
Common conversions
- What is 9:00 am MST in ART?
- 9:00 am MST is 12:00 pm ART.
- What is 12:00 pm MST in ART?
- 12:00 pm MST is 3:00 pm ART.
- What is 12:30 pm MST in ART?
- 12:30 pm MST is 3:30 pm ART.
- What is 2:00 pm MST in ART?
- 2:00 pm MST is 5:00 pm ART.
- What is 5:00 pm MST in ART?
- 5:00 pm MST is 8:00 pm ART.
- What is 11:30 pm MST in ART?
- 11:30 pm MST is 2:30 am ART, the next day.