Convert IRST to NZST
NZST is 8 hours 30 minutes ahead of IRST. IRST is UTC+3:30 and NZST is UTC+12.
Right now: IRST · NZST
Best time to schedule a meeting
Standard 9–5 working hours do not overlap at all between IRST and NZST. Someone has to take an early or late call — or use asynchronous communication instead.
| IRST | NZST | Suitable? |
|---|---|---|
| 9:00 AM | 5:30 PM | outside 9–5 |
| 10:00 AM | 6:30 PM | outside 9–5 |
| 11:00 AM | 7:30 PM | outside 9–5 |
| 12:00 PM | 8:30 PM | outside 9–5 |
| 1:00 PM | 9:30 PM | outside 9–5 |
| 2:00 PM | 10:30 PM | outside 9–5 |
| 3:00 PM | 11:30 PM | outside 9–5 |
| 4:00 PM | 12:30 AM (next day) | outside 9–5 |
| 5:00 PM | 1:30 AM (next day) | outside 9–5 |
IRST to NZST conversion table
| IRST | NZST |
|---|---|
| 12:00 AM | 8:30 AM |
| 1:00 AM | 9:30 AM |
| 2:00 AM | 10:30 AM |
| 3:00 AM | 11:30 AM |
| 4:00 AM | 12:30 PM |
| 5:00 AM | 1:30 PM |
| 6:00 AM | 2:30 PM |
| 7:00 AM | 3:30 PM |
| 8:00 AM | 4:30 PM |
| 9:00 AM | 5:30 PM |
| 10:00 AM | 6:30 PM |
| 11:00 AM | 7:30 PM |
| 12:00 PM | 8:30 PM |
| 1:00 PM | 9:30 PM |
| 2:00 PM | 10:30 PM |
| 3:00 PM | 11:30 PM |
| 4:00 PM | 12:30 AM (next day) |
| 5:00 PM | 1:30 AM (next day) |
| 6:00 PM | 2:30 AM (next day) |
| 7:00 PM | 3:30 AM (next day) |
| 8:00 PM | 4:30 AM (next day) |
| 9:00 PM | 5:30 AM (next day) |
| 10:00 PM | 6:30 AM (next day) |
| 11:00 PM | 7:30 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 NZST
New Zealand Standard Time (NZST) is UTC+12. It is used in Auckland and Wellington in the southern winter.
New Zealand Standard Time is UTC+12, the furthest ahead of the commonly used abbreviations, moving to NZDT at UTC+13 from late September to early April. New Zealand is where the date changes first for most of the world's working population, which is why release schedules and financial rollovers are often expressed relative to it. Chatham Islands time, at UTC+12:45, is one of only three quarter-hour offsets in use anywhere.
Does this gap change with the seasons?
Neither IRST nor NZST shifts with the seasons, so this 8.5-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 NZST?
9:00 AM IRST is 5:30 PM NZST.
Is NZST ahead of IRST?
NZST is 8 hours 30 minutes ahead of IRST.
Which time zone does this use?
IRST is UTC+3:30 and NZST is UTC+12. 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.