Convert IRST to NZDT
NZDT is 9 hours 30 minutes ahead of IRST. IRST is UTC+3:30 and NZDT is UTC+13.
Right now: IRST · NZDT
Best time to schedule a meeting
Standard 9–5 working hours do not overlap at all between IRST and NZDT. Someone has to take an early or late call — or use asynchronous communication instead.
| IRST | NZDT | Suitable? |
|---|---|---|
| 9:00 AM | 6:30 PM | outside 9–5 |
| 10:00 AM | 7:30 PM | outside 9–5 |
| 11:00 AM | 8:30 PM | outside 9–5 |
| 12:00 PM | 9:30 PM | outside 9–5 |
| 1:00 PM | 10:30 PM | outside 9–5 |
| 2:00 PM | 11:30 PM | outside 9–5 |
| 3:00 PM | 12:30 AM (next day) | outside 9–5 |
| 4:00 PM | 1:30 AM (next day) | outside 9–5 |
| 5:00 PM | 2:30 AM (next day) | outside 9–5 |
IRST to NZDT conversion table
| IRST | NZDT |
|---|---|
| 12:00 AM | 9:30 AM |
| 1:00 AM | 10:30 AM |
| 2:00 AM | 11:30 AM |
| 3:00 AM | 12:30 PM |
| 4:00 AM | 1:30 PM |
| 5:00 AM | 2:30 PM |
| 6:00 AM | 3:30 PM |
| 7:00 AM | 4:30 PM |
| 8:00 AM | 5:30 PM |
| 9:00 AM | 6:30 PM |
| 10:00 AM | 7:30 PM |
| 11:00 AM | 8:30 PM |
| 12:00 PM | 9:30 PM |
| 1:00 PM | 10:30 PM |
| 2:00 PM | 11:30 PM |
| 3:00 PM | 12:30 AM (next day) |
| 4:00 PM | 1:30 AM (next day) |
| 5:00 PM | 2:30 AM (next day) |
| 6:00 PM | 3:30 AM (next day) |
| 7:00 PM | 4:30 AM (next day) |
| 8:00 PM | 5:30 AM (next day) |
| 9:00 PM | 6:30 AM (next day) |
| 10:00 PM | 7:30 AM (next day) |
| 11:00 PM | 8:30 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 NZDT
New Zealand Daylight Time (NZDT) is UTC+13. It is used in New Zealand from late September to early April.
New Zealand Daylight Time is UTC+13, one of the few offsets past twelve hours and therefore a full calendar day ahead of most of the Americas. New Zealand's summer is the northern hemisphere's winter, so NZDT applies over Christmas — the opposite of every northern daylight-saving abbreviation, and a common mistake in end-of-year scheduling.
Does this gap change with the seasons?
Neither IRST nor NZDT shifts with the seasons, so this 9.5-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 NZDT?
9:00 AM IRST is 6:30 PM NZDT.
Is NZDT ahead of IRST?
NZDT is 9 hours 30 minutes ahead of IRST.
Which time zone does this use?
IRST is UTC+3:30 and NZDT is UTC+13. 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.