Convert IRST to BDT
BDT is 2 hours 30 minutes ahead of IRST. IRST is UTC+3:30 and BDT is UTC+6.
Right now: IRST · BDT
Best time to schedule a meeting
Standard 9–5 working hours overlap for 6 hours: 9:00 AM–3:00 PM IRST (11:00 AM–5:00 PM BDT). Schedule meetings inside that window.
| IRST | BDT | Suitable? |
|---|---|---|
| 9:00 AM | 11:30 AM | working hours |
| 10:00 AM | 12:30 PM | working hours |
| 11:00 AM | 1:30 PM | working hours |
| 12:00 PM | 2:30 PM | working hours |
| 1:00 PM | 3:30 PM | working hours |
| 2:00 PM | 4:30 PM | working hours |
| 3:00 PM | 5:30 PM | outside 9–5 |
| 4:00 PM | 6:30 PM | outside 9–5 |
| 5:00 PM | 7:30 PM | outside 9–5 |
IRST to BDT conversion table
| IRST | BDT |
|---|---|
| 12:00 AM | 2:30 AM |
| 1:00 AM | 3:30 AM |
| 2:00 AM | 4:30 AM |
| 3:00 AM | 5:30 AM |
| 4:00 AM | 6:30 AM |
| 5:00 AM | 7:30 AM |
| 6:00 AM | 8:30 AM |
| 7:00 AM | 9:30 AM |
| 8:00 AM | 10:30 AM |
| 9:00 AM | 11:30 AM |
| 10:00 AM | 12:30 PM |
| 11:00 AM | 1:30 PM |
| 12:00 PM | 2:30 PM |
| 1:00 PM | 3:30 PM |
| 2:00 PM | 4:30 PM |
| 3:00 PM | 5:30 PM |
| 4:00 PM | 6:30 PM |
| 5:00 PM | 7:30 PM |
| 6:00 PM | 8:30 PM |
| 7:00 PM | 9:30 PM |
| 8:00 PM | 10:30 PM |
| 9:00 PM | 11:30 PM |
| 10:00 PM | 12:30 AM (next day) |
| 11:00 PM | 1:30 AM (next day) |
About IRST
Iran Standard Time (IRST) is UTC+3:30. It is used in Iran, all year.
Iran Standard Time is UTC+3:30. Iran ran daylight saving for decades and stopped in 2022, so material written before then puts the country half an hour further ahead in summer and is now wrong. Half-hour offsets are rare enough that scheduling tools sometimes round them, which turns a correct calculation into a thirty-minute error.
About BDT
Bangladesh Standard Time (BDT) is UTC+6. It is used in Bangladesh, all year.
Bangladesh Standard Time is UTC+6 with no daylight saving. It is more often written BST, which is where the trouble starts: BST also means British Summer Time at UTC+1, and the two readings are five hours apart. Converter sites split on which they answer for and rarely say. BDT is the unambiguous way to write it, and worth using in anything that matters.
Does this gap change with the seasons?
Neither IRST nor BDT shifts with the seasons, so this 2.5-hour difference holds all year. That is unusual enough to be worth relying on: most cross-continental gaps move twice a year.
This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.
Frequently asked questions
What time is 9:00 AM IRST in BDT?
9:00 AM IRST is 11:30 AM BDT.
Is BDT ahead of IRST?
BDT is 2 hours 30 minutes ahead of IRST.
Which time zone does this use?
IRST is UTC+3:30 and BDT is UTC+6. Both abbreviations denote a single fixed offset, so this conversion never shifts with daylight saving — what changes is which abbreviation a place is using at the time.