IRST to MST/MDT time converter

MST/MDT is 9 hours 30 minutes behind IRST. When it is 9:00 AM in IRST, it is 11:30 PM (Fri, Oct 16) in MST/MDT.

IRST UTC+3:30

Saturday, October 17, 2026

MST/MDT MDT

Friday, October 16, 2026

IRST
Iran Standard Time
Sat, Oct 17
UTC+3:30
MST/MDT
Mountain Standard Time
Fri, Oct 16
MDTUTC-6-9h 30m
Finding your time zone…
Shared working hours (9:00–18:00)

IRST to MST/MDT conversion table

Every hour of today in IRST and the matching time in MST/MDT. Light rows are typical working hours (9:00–18:00).

IRSTMST/MDT
12:00 AM2:30 PM−1 day
1:00 AM3:30 PM−1 day
2:00 AM4:30 PM−1 day
3:00 AM5:30 PM−1 day
4:00 AM6:30 PM−1 day
5:00 AM7:30 PM−1 day
6:00 AM8:30 PM−1 day
7:00 AM9:30 PM−1 day
8:00 AM10:30 PM−1 day
9:00 AM11:30 PM−1 day
10:00 AM12:30 AM
11:00 AM1:30 AM
12:00 PM2:30 AM
1:00 PM3:30 AM
2:00 PM4:30 AM
3:00 PM5:30 AM
4:00 PM6:30 AM
5:00 PM7:30 AM
6:00 PM8:30 AM
7:00 PM9:30 AM
8:00 PM10:30 AM
9:00 PM11:30 AM
10:00 PM12:30 PM
11:00 PM1:30 PM

Best time to call or meet

Working hours don't overlap fully. The closest fit is 4:30 PM – 6:00 PM in IRST (7:00 AM – 8:30 AM in MST/MDT): working hours on one side, early or late on the other.

Daylight saving time and the difference

The difference changes during the year because IRST and MST/MDT switch clocks on different dates:

  • Oct 17, 2026 – Nov 1, 2026: -9h 30m
  • Nov 1, 2026 – Mar 14, 2027: -10h 30m
  • Mar 14, 2027 – Oct 17, 2027: -9h 30m

More conversions

MST to IRSTIRST to UTCIRST to GMTIRST to ESTIRST to CSTIRST to PSTIRST to CETIRST to MSKIRST to GSTIRST to PKTIRST to ISTIRST to SGTIRST to PHT
UTC to MSTGMT to MSTEST to MSTCST to MSTPST to MSTCET to MSTMSK to MSTGST to MSTPKT to MSTIST to MSTSGT to MSTPHT to MST

Questions and answers

What is the time difference between IRST and MST/MDT?

MST/MDT is 9 hours 30 minutes behind IRST.

What time is it in MST/MDT when it is 9 AM in IRST?

When it is 9:00 AM in IRST, it is 11:30 PM (Fri, Oct 16) in MST/MDT.

When is the best time to call MST/MDT from IRST?

Working hours don't overlap fully. The closest fit is 4:30 PM – 6:00 PM in IRST (7:00 AM – 8:30 AM in MST/MDT): working hours on one side, early or late on the other.

Does the time difference between IRST and MST/MDT change?

Yes, for part of the year, because daylight saving time starts and ends on different dates or applies on one side only.