Convert ACDT to IRST
IRST is 7 hours behind ACDT. ACDT is UTC+10:30 and IRST is UTC+3:30.
Right now: ACDT · IRST
Best time to schedule a meeting
Standard 9–5 working hours overlap for 1 hour: 4:00 PM–5:00 PM ACDT (9:00 AM–10:00 AM IRST). Schedule meetings inside that window.
| ACDT | IRST | Suitable? |
|---|---|---|
| 9:00 AM | 2:00 AM | outside 9–5 |
| 10:00 AM | 3:00 AM | outside 9–5 |
| 11:00 AM | 4:00 AM | outside 9–5 |
| 12:00 PM | 5:00 AM | outside 9–5 |
| 1:00 PM | 6:00 AM | outside 9–5 |
| 2:00 PM | 7:00 AM | outside 9–5 |
| 3:00 PM | 8:00 AM | outside 9–5 |
| 4:00 PM | 9:00 AM | working hours |
| 5:00 PM | 10:00 AM | working hours |
ACDT to IRST conversion table
| ACDT | IRST |
|---|---|
| 12:00 AM | 5:00 PM (previous day) |
| 1:00 AM | 6:00 PM (previous day) |
| 2:00 AM | 7:00 PM (previous day) |
| 3:00 AM | 8:00 PM (previous day) |
| 4:00 AM | 9:00 PM (previous day) |
| 5:00 AM | 10:00 PM (previous day) |
| 6:00 AM | 11:00 PM (previous day) |
| 7:00 AM | 12:00 AM |
| 8:00 AM | 1:00 AM |
| 9:00 AM | 2:00 AM |
| 10:00 AM | 3:00 AM |
| 11:00 AM | 4:00 AM |
| 12:00 PM | 5:00 AM |
| 1:00 PM | 6:00 AM |
| 2:00 PM | 7:00 AM |
| 3:00 PM | 8:00 AM |
| 4:00 PM | 9:00 AM |
| 5:00 PM | 10:00 AM |
| 6:00 PM | 11:00 AM |
| 7:00 PM | 12:00 PM |
| 8:00 PM | 1:00 PM |
| 9:00 PM | 2:00 PM |
| 10:00 PM | 3:00 PM |
| 11:00 PM | 4:00 PM |
About ACDT
Australian Central Daylight Time (ACDT) is UTC+10:30. It is used in Adelaide in summer.
Australian Central Daylight Time is UTC+10:30, what South Australia keeps from October to April. Darwin stays on ACST through the summer, so for those months two cities in the same nominal zone are an hour apart — the only reason to be precise about which of the two abbreviations a meeting invitation carries.
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.
Does this gap change with the seasons?
Neither ACDT nor IRST shifts with the seasons, so this 7-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 ACDT in IRST?
9:00 AM ACDT is 2:00 AM IRST.
Is IRST ahead of ACDT?
IRST is 7 hours behind ACDT.
Which time zone does this use?
ACDT is UTC+10:30 and IRST is UTC+3:30. 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.