What is the time difference between BDT and IRST?

Iran Standard Time (IRST) is 2 hours and 30 minutes behind Bangladesh Standard Time (BDT). BDT uses a UTC offset of UTC+6, while IRST uses UTC+3:30. For example, when it's 9:00 AM in BDT, it's 6:30 AM in IRST. 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 BDT to IRST?

To convert BDT to IRST, subtract 2 hours and 30 minutes from the BDT time. For example, 9:00 AM BDT is 6:30 AM IRST, and 5:00 PM BDT is 2:30 PM IRST. 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 IRST when it's noon in BDT?

When it's 12:00 PM (noon) in BDT, it's 9:30 AM in IRST. This is because IRST is 2 hours and 30 minutes behind BDT. Similarly, when it's 6:00 PM in BDT, it's 3:30 PM in IRST. This relationship is constant throughout the year. The color-coded conversion table above shows every hour mapped between both timezones.

How many hours behind is IRST from BDT?

IRST is 2 hours and 30 minutes behind BDT. This means when it's 9:00 AM in BDT, it's 6:30 AM in IRST, and when it's midnight in BDT, it's 9:30 PM in IRST. 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 IRST ahead or behind BDT?

IRST is behind BDT by 2 hours and 30 minutes. Clocks in IRST show an earlier time than BDT, meaning the day starts later in IRST relative to BDT. For example, when it's noon in BDT, it's still 9:30 AM in IRST. This difference stays the same year-round.

Does BDT observe daylight saving time?

No, Bangladesh Standard Time does not observe daylight saving time. The UTC offset of UTC+6 remains the same year-round, which simplifies time conversions. Regions using BDT keep their clocks unchanged regardless of the season.

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.

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

The best time for a call between BDT and IRST is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in IRST during their work day, call between 11:30 AM and 7:30 PM your BDT time. Avoid calling too early or late, as the 2 hours and 30 minutes difference means your evening could be their early morning. Check the color-coded conversion table above — green hours indicate business hours in both zones, making it easy to find the ideal time.

Do BDT and IRST ever have the same time?

No, BDT and IRST are always 2 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 2 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.

BDT to IRST Converter

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

Timezone Details

Dhaka

1:31 PM

Tuesday, September 8, 2026

Dhaka (UTC+06:00)

Tehran

11:01 AM

Tuesday, September 8, 2026

Tehran (UTC+03:30)

Difference: -2h 30m

24-Hour Overview

Dhaka — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

Tehran — 24-hour overview

9p9p

10p

11p

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

IRST to BDT

Cities in These Timezones

BDT Cities

Dhaka Chittagong

IRST Cities

Tehran

More Tools

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

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

IANA Time Zone Database