What is the time difference between IRST and ICT?

Indochina Time (ICT) is 3 hours and 30 minutes ahead of Iran Standard Time (IRST). IRST uses a UTC offset of UTC+3:30, while ICT uses UTC+7. For example, when it's 9:00 AM in IRST, it's 12:30 PM in ICT. This difference remains constant year-round since neither timezone observes daylight saving time. Use the conversion table above to see the exact time for each hour of the day.

How do I convert IRST to ICT?

To convert IRST to ICT, add 3 hours and 30 minutes to the IRST time. For example, 9:00 AM IRST is 12:30 PM ICT, and 5:00 PM IRST is 8:30 PM ICT. Since neither timezone observes DST, this conversion stays the same all year. You can also use the interactive converter above for quick, accurate results.

What time is it in ICT when it's noon in IRST?

When it's 12:00 PM (noon) in IRST, it's 3:30 PM in ICT. This is because ICT is 3 hours and 30 minutes ahead of IRST. Similarly, when it's 6:00 PM in IRST, it's 9:30 PM in ICT. This relationship is constant throughout the year. The color-coded conversion table above shows every hour mapped between both timezones.

How many hours ahead is ICT from IRST?

ICT is 3 hours and 30 minutes ahead of IRST. This means when it's 9:00 AM in IRST, it's 12:30 PM in ICT, and when it's midnight in IRST, it's 3:30 AM in ICT. This offset is constant throughout the year since neither timezone uses daylight saving time. The conversion table above provides a complete hour-by-hour mapping.

Is ICT ahead or behind IRST?

ICT is ahead of IRST by 3 hours and 30 minutes. Clocks in ICT show a later time than IRST, meaning the day starts earlier in ICT relative to IRST. For example, when it's morning in IRST, it's later in the morning in ICT. This difference stays the same year-round.

Does IRST observe daylight saving time?

No, Iran Standard Time does not observe daylight saving time. The UTC offset of UTC+3:30 remains the same year-round, which simplifies time conversions. Regions using IRST keep their clocks unchanged regardless of the season.

Does ICT observe daylight saving time?

No, Indochina Time does not observe daylight saving time. The UTC offset of UTC+7 remains the same year-round, making time conversions to ICT more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

What is the best time to call from IRST to ICT?

The best time for a call between IRST and ICT is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in ICT during their work day, call between 5:30 AM and 1:30 PM your IRST time. Avoid calling too early or late, as the 3 hours and 30 minutes difference means your evening could be their late night. Check the color-coded conversion table above — green hours indicate business hours in both zones, making it easy to find the ideal time.

Do IRST and ICT ever have the same time?

No, IRST and ICT are always 3 hours and 30 minutes apart and never display the same clock time simultaneously. Neither timezone observes DST, so the difference is constant year-round with no seasonal variation. The 3 hours and 30 minutes offset is determined by their fixed positions relative to the Prime Meridian (UTC). You can always rely on this consistent difference when planning across these timezones.

IRST to ICT Converter

Convert Iran Standard Time to Indochina Time. See the hour-by-hour conversion table below.

Timezone Details

Tehran

1:34 PM

Friday, April 3, 2026

Tehran (UTC+03:30)

Indochina Time

5:04 PM

Friday, April 3, 2026

ICT (UTC+07:00)

Difference: +3h 30m

ICT DST: No

24-Hour Overview

Tehran — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

ICT — 24-hour overview

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

12a12a

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

ICT to IRST

Cities in These Timezones

IRST Cities

Tehran

ICT Cities

Bangkok Phuket Chiang Mai

More Tools

Compare IRST & ICT Plan a Meeting (IRST & ICT)See on Map

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Indochina Time on Wikipedia IANA Time Zone Database