UTC to IRST Time Converter

Common Times Converted

UTC on the left, IRST on the right.

UTC to IRST: Full 24-Hour Conversion Table

Shaded rows are working hours; the darker shade marks the hours when both zones are at work.

What UTC and IRST Actually Are

UTC — Coordinated Universal Time

The global reference standard. Aviation, computing and science run on it. Standing at UTC as written, and the region does not change its clocks, so that offset holds all year.

UTC is not a place. It is a computed standard, kept within a second of mean solar time at Greenwich by atomic clocks, and it is the reference every other zone is defined against.

IRST — Iran Standard Time

Tehran, Mashhad, Isfahan. Standing at UTC+3:30 as written, and the region does not change its clocks, so that offset holds all year. Iran abolished daylight saving in 2022, so the half-hour offset now holds all year.

Iran abolished daylight saving in 2022. Its half-hour offset is a deliberate compromise between the solar times of its western and eastern borders.

What This Means in Practice

Expect times on the half hour

IRST sits on a 30-minute offset rather than a whole hour, so a round number on one side is never a round number on the other. A 9:00 meeting becomes 30 minutes past the hour, which is exactly the detail calendar invitations get wrong when someone converts in their head.

A gap you can rely on

Neither region changes its clocks, so this difference holds every day of the year. A recurring meeting booked once stays correct — worth knowing, because most cross-border pairs cannot say that.

Major Cities in Each Zone

Cities on IRST