IRST to MST converter

Iran Time (Tehran) to Mountain Time (Denver, Salt Lake City, Calgary).

IRST3:37 AMSat 31 Oct 2026

→

MST6:07 PMFri 30 Oct 2026

MST is 9 h 30 min behind IRST.

Pick a time in IRST

⇄ MST to IRST

9:00 AM IRST = 11:30 PM MST previous day

Best time to meet

No hour falls inside 9 AM to 5 PM in both places. The least painful: around 7:00 PM IRST, which is 9:30 AM MST.

IRST to MST time table

For 31 Oct 2026. Green rows: both sides between 9 AM and 5 PM.

IRST	MST
12:00 AM IRST	2:30 PM MST previous day
1:00 AM IRST	3:30 PM MST previous day
2:00 AM IRST	4:30 PM MST previous day
3:00 AM IRST	5:30 PM MST previous day
4:00 AM IRST	6:30 PM MST previous day
5:00 AM IRST	7:30 PM MST previous day
6:00 AM IRST	8:30 PM MST previous day
7:00 AM IRST	9:30 PM MST previous day
8:00 AM IRST	10:30 PM MST previous day
9:00 AM IRST	11:30 PM MST previous day
10:00 AM IRST	12:30 AM MST
11:00 AM IRST	1:30 AM MST
12:00 PM IRST	2:30 AM MST
1:00 PM IRST	3:30 AM MST
2:00 PM IRST	4:30 AM MST
3:00 PM IRST	5:30 AM MST
4:00 PM IRST	6:30 AM MST
5:00 PM IRST	7:30 AM MST
6:00 PM IRST	8:30 AM MST
7:00 PM IRST	9:30 AM MST
8:00 PM IRST	10:30 AM MST
9:00 PM IRST	11:30 AM MST
10:00 PM IRST	12:30 PM MST
11:00 PM IRST	1:30 PM MST

Quick answers

9:00 AM IRST = 11:30 PM MST (previous day)
12:00 PM IRST = 2:30 AM MST
3:00 PM IRST = 5:30 AM MST
5:00 PM IRST = 7:30 AM MST
9:00 AM MST = 6:30 PM IRST
12:00 PM MST = 9:30 PM IRST
5:00 PM MST = 2:30 AM IRST (next day)

Does the gap change during the year?

Yes, because of daylight saving. Until 1 Nov 2026: MST is 9 h 30 min behind IRST. From 1 Nov 2026 to 14 Mar 2027: MST is 10 h 30 min behind IRST. From 14 Mar 2027 to 7 Nov 2027: MST is 9 h 30 min behind IRST.

IRST does not change its clocks. MST next changes its clocks on 1 Nov 2026 (back 1 h, to UTC−7), then on 14 Mar 2027 (forward 1 h, to UTC−6).

About IRST and MST

IRST here means Iran Time, the clock in Tehran. Right now it is UTC+3:30. It has no daylight saving.

MST here means Mountain Time, the clock in Denver, Salt Lake City, Calgary. Right now it is UTC−6. Strictly, MST is the winter name; in summer these places use MDT. This page follows their real clock all year.

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