Halifax to IRST
+6h 30mHalifax
ADTSOURCEIRST
IRSTGreen rows indicate typical business hours (9 AM - 5 PM)
ADT and IRST on the World Map
The map below highlights the ADT (Atlantic Standard Time) and IRST (Iran Standard Time) timezone regions across the globe.
AST – Atlantic Standard Time
UTC-04:00Atlantic Standard Time (AST) is the time zone for the Canadian Atlantic provinces and the Caribbean, 4 hours behind UTC.
- •Puerto Rico uses AST year-round and does not observe DST.
- •AST is 1 hour ahead of EST.
- •Halifax, the capital of Nova Scotia, is the largest city in AST Canada.
IRST – Iran Standard Time
UTC+03:30Iran Standard Time (IRST) is the time zone for Iran, 3 hours and 30 minutes ahead of UTC.
- •IRST is one of only a few time zones with a 30-minute offset.
- •Iran observes daylight saving time, switching to IRDT (UTC+04:30).
- •Tehran has a metropolitan population of over 16 million.
About Halifax
WikipediaHalifax operates on Atlantic Time (AST/ADT), UTC-4. As Canada's major Atlantic port and closest city to Europe, Halifax bridges North American and European business.
Halifax harbors the second largest natural ice-free harbor in the world.
Everything You Need to Know About Halifax and IRST Time
Halifax runs on Atlantic Daylight Time (ADT) at UTC-03:00, currently observing daylight saving time. IRST runs on Iran Standard Time (IRST) at UTC+03:30. That puts Halifax 6 hours 30 minutes ahead of IRST — a difference of +6h 30m at the current offsets.
In practice, when it is 9:00 AM in Halifax it is 3:30 PM in IRST. Midnight in Halifax is 6:30 AM in IRST.Halifax observes daylight saving time while IRST does not, so the gap narrows or widens by an hour part of the year.
Halifax to IRST time conversion table
| Halifax (ADT) | IRST (IRST) | Day |
|---|---|---|
| 12:00 AM | 6:30 AM | same day |
| 6:00 AM | 12:30 PM | same day |
| 7:00 AM | 1:30 PM | same day |
| 8:00 AM | 2:30 PM | same day |
| 9:00 AM | 3:30 PM | same day |
| 12:00 PM | 6:30 PM | same day |
| 3:00 PM | 9:30 PM | same day |
| 5:00 PM | 11:30 PM | same day |
| 6:00 PM | 12:30 AM | next day |
| 9:00 PM | 3:30 AM | next day |
Why people convert Halifax to IRST time
- Scheduling a call from Halifax to IRST: a 10:00 AM start in Halifax lands at 4:30 PM in IRST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Halifax and IRST are inside the 9-to-5 working day between 9:00 AM and 10:30 AM ADT time (3:30 PM–5:00 PM IRST). That is roughly 1 hours 30 minutes of usable overlap.
- Coordinating a Halifax-based team with IRST contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
- Always state the zone abbreviation, not just the hour. "3:00 PM ADT" is unambiguous; "3 PM" across a +6h 30m gap is not.
- Block 9:00 AM–10:30 AM ADT as the recurring meeting window if you work primarily from Halifax and need IRST colleagues present.
- Halifax: Clocks fall back on Sun, Nov 1, 2026. Re-check this page after that date because the offset changes and so does the +6h 30m gap.
About AST (Atlantic Standard Time)
Atlantic Standard Time (AST) covers Canada's Atlantic provinces (Nova Scotia, New Brunswick, Prince Edward Island, and most of Labrador), as well as several Caribbean nations. Puerto Rico and the US Virgin Islands use AST year-round without daylight saving time. The Canadian provinces switch to Atlantic Daylight Time (ADT) in summer.
About IRST (Iran Standard Time)
Iran Standard Time (IRST) is one of the few time zones with a 30-minute offset. Iran observes daylight saving time (IRDT, UTC+04:30) from late March to late September. Tehran, the capital, is one of the largest cities in the Middle East.
Best time to call between Halifax and IRST
Both Halifax and IRST sit inside the 9 AM – 5 PM working day between 9:00 AM–10:30 AM ADT, which is 3:30 PM–5:00 PM IRST. That gives roughly 1 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
Halifax and IRST overlap for only 90 minutes (9:00 AM–10:30 AM ADT), so meetings have to be booked precisely.
Halifax is 6 hours 30 minutes ahead of IRST (ADT UTC-03:00 → IRST UTC+03:30). The shared working window is 9:00 AM–10:30 AM ADT. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Halifax
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Nov 1, 2026
IRST
Does not observe DST
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between Halifax and IRST?
Halifax (ADT, UTC-03:00) is 6 hours 30 minutes ahead of IRST (IRST, UTC+03:30). The gap is currently +6h 30m.
How do I convert Halifax time to IRST time?
Add +6h 30m to Halifax local time. For example, 9:00 AM in Halifax is 3:30 PM in IRST.
What time is it in IRST right now?
IRST uses IRST at UTC+03:30. Use the live converter at the top of this page — it updates in real time and already accounts for the +6h 30m offset from Halifax.
What is the best time to call IRST from Halifax?
Call between 9:00 AM and 10:30 AM ADT — that maps to 3:30 PM–5:00 PM IRST and keeps both parties inside the working day.
Which is ahead, Halifax or IRST?
Halifax is 6 hours 30 minutes ahead of IRST. When it is 12:00 PM in Halifax it is 6:30 PM in IRST.
Do Halifax and IRST use different time zones?
Halifax (Canada) uses ADT at UTC-03:00, while IRST uses IRST at UTC+03:30. The IANA identifiers are America/Halifax and Asia/Tehran.
Does daylight saving time affect the Halifax–IRST difference?
Yes at the moment: Halifax is on daylight saving time and IRST is not, so the +6h 30m gap shifts by an hour when exactly one of them changes clocks.
Which other cities share Halifax's time zone?
ADT also covers Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.
Which countries use ADT, Halifax's zone?
ADT is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, Barbados, Trinidad and Tobago.
Is there a day difference between Halifax and IRST?
Not normally. The +6h 30m gap only pushes the date over for late-evening times.
What is the time difference between Halifax and IRST?
IRST is +6h 30m from Halifax.
What timezone is Halifax in?
Halifax operates on Atlantic Time (AST/ADT), UTC-4. As Canada's major Atlantic port and closest city to Europe, Halifax bridges North American and European business.
What timezone is IRST in?
IRST operates on its local timezone.
What are the business hours in Halifax?
Standard business hours in Halifax are 9:00 AM - 5:00 PM AST.
Which countries use AST (Atlantic Standard Time)?
AST is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, and 2 more countries.
Does AST observe daylight saving time?
Yes, AST switches to ADT during summer months.
What are some interesting facts about AST?
Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.
Which cities are in the IRST timezone?
Major cities in the IRST timezone include Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
What is the UTC offset for IRST?
Iran Standard Time (IRST) is at UTC+03:30. During daylight saving time, it shifts to IRDT.
What should I know about the IRST timezone?
IRST is one of only a few time zones with a 30-minute offset. Iran observes daylight saving time, switching to IRDT (UTC+04:30).
When is it midnight in Halifax, what time is it in IRST?
When it is 12:00 AM (midnight) in Halifax (AST), it is +6h 30m later in IRST (IRST).
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