IRST to Riyadh
-0h 30mIRST
IRSTSOURCERiyadh
ASTGreen rows indicate typical business hours (9 AM - 5 PM)
IRST and AST on the World Map
The map below highlights the IRST (Iran Standard Time) and AST (Arabia Standard Time) timezone regions across the globe.
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.
AST – Arabia Standard Time
UTC+03:00Arabia Standard Time (AST, UTC+03:00) is the time zone for Saudi Arabia and the other Gulf states of the Arabian peninsula.
- •None of the Gulf states on Arabia Standard Time observe daylight saving.
- •AST is the same offset as Moscow Standard Time and East Africa Time.
- •Riyadh is one hour ahead of Central European Time in winter.
- •The AST abbreviation is shared with Atlantic Standard Time (UTC-04:00).
About Riyadh
WikipediaRiyadh operates on Arabia Standard Time (AST), UTC+3. As OPEC's de facto capital and home to Tadawul, Riyadh time impacts global energy markets.
Riyadh is growing rapidly as part of Saudi Vision 2030 modernization.
IRST to Riyadh Time Difference – Complete Guide
IRST runs on Iran Standard Time (IRST) at UTC+03:30. Riyadh runs on Arabian Standard Time (AST) at UTC+03:00. That puts IRST 30 minutes behind Riyadh — a difference of -0h 30m at the current offsets.
In practice, when it is 9:00 AM in IRST it is 8:30 AM in Riyadh. Midnight in IRST is 11:30 PM in Riyadh. Neither zone observes daylight saving time, so the offset between them stays constant all year.
IRST to Riyadh time conversion table
| IRST (IRST) | Riyadh (AST) | Day |
|---|---|---|
| 12:00 AM | 11:30 PM | previous day |
| 6:00 AM | 5:30 AM | same day |
| 7:00 AM | 6:30 AM | same day |
| 8:00 AM | 7:30 AM | same day |
| 9:00 AM | 8:30 AM | same day |
| 12:00 PM | 11:30 AM | same day |
| 3:00 PM | 2:30 PM | same day |
| 5:00 PM | 4:30 PM | same day |
| 6:00 PM | 5:30 PM | same day |
| 9:00 PM | 8:30 PM | same day |
Why people convert IRST to Riyadh time
- Scheduling a call from IRST to Riyadh: a 10:00 AM start in IRST lands at 9:30 AM in Riyadh, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both IRST and Riyadh are inside the 9-to-5 working day between 9:30 AM and 5:00 PM IRST time (9:00 AM–4:30 PM AST). That is roughly 7 hours 30 minutes of usable overlap.
- Watching a live event or market open: IRST viewers need 8:30 AM in Riyadh to catch a 9:00 AM start there, and 12:30 AM if the event is anchored to IRST.
- Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a -0h 30m gap is not.
- Block 9:30 AM–5:00 PM IRST as the recurring meeting window if you work primarily from IRST and need Riyadh colleagues present.
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.
About AST (Arabia Standard Time)
Arabia Standard Time (AST) is fixed at UTC+03:00 all year across Saudi Arabia, Qatar, Kuwait, Bahrain, Iraq and Yemen. None of these countries observes daylight saving time, so the offset never changes. The abbreviation collides with Atlantic Standard Time (UTC-04:00) used in eastern Canada and the Caribbean; this page covers the Arabian peninsula meaning. Arabia Standard Time is the same offset as Moscow Standard Time and East Africa Time, which makes scheduling with Europe straightforward — Riyadh is one hour ahead of Central European Time in winter and level with it during European summer time.
Best time to call between IRST and Riyadh
Both IRST and Riyadh sit inside the 9 AM – 5 PM working day between 9:30 AM–5:00 PM IRST, which is 9:00 AM–4:30 PM AST. That gives roughly 7 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
IRST and Riyadh share 7 hours of working-hours overlap (9:30 AM–5:00 PM IRST), so scheduling a live meeting is straightforward.
IRST is 30 minutes behind Riyadh (IRST UTC+03:30 → AST UTC+03:00). The shared working window is 9:30 AM–5:00 PM IRST. Remember to re-check around daylight-saving transitions.
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 IRST and Riyadh?
IRST (IRST, UTC+03:30) is 30 minutes behind Riyadh (AST, UTC+03:00). The gap is currently -0h 30m.
How do I convert IRST time to Riyadh time?
Add -0h 30m to IRST local time. For example, 9:00 AM in IRST is 8:30 AM in Riyadh.
What time is it in Riyadh right now?
Riyadh uses AST at UTC+03:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -0h 30m offset from IRST.
What is the best time to call Riyadh from IRST?
Call between 9:30 AM and 5:00 PM IRST — that maps to 9:00 AM–4:30 PM AST and keeps both parties inside the working day.
Which is behind, IRST or Riyadh?
IRST is 30 minutes behind Riyadh. When it is 12:00 PM in IRST it is 11:30 AM in Riyadh.
Do IRST and Riyadh use different time zones?
IRST uses IRST at UTC+03:30, while Riyadh (Saudi Arabia) uses AST at UTC+03:00. The IANA identifiers are Asia/Tehran and Asia/Riyadh.
Does daylight saving time affect the IRST–Riyadh difference?
Neither zone observes daylight saving time, so the -0h 30m offset between IRST and Riyadh is fixed all year.
Which other cities share IRST's time zone?
IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
Which countries use IRST, IRST's zone?
IRST is used in Iran.
Is there a day difference between IRST and Riyadh?
Not normally. The -0h 30m gap only pushes the date over the previous day.
What is the time difference between IRST and Riyadh?
Riyadh is -0h 30m from IRST.
What timezone is IRST in?
IRST operates on its local timezone.
What timezone is Riyadh in?
Riyadh operates on Arabia Standard Time (AST), UTC+3. As OPEC's de facto capital and home to Tadawul, Riyadh time impacts global energy markets.
What are the business hours in Riyadh?
Standard business hours in Riyadh are 8:00 AM - 4:00 PM AST (Sunday-Thursday).
Which countries use IRST (Iran Standard Time)?
IRST is used in Iran.
Does IRST observe daylight saving time?
Yes, IRST switches to IRDT during summer months.
What are some interesting facts about IRST?
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).
Which cities are in the AST timezone?
Major cities in the AST timezone include Riyadh, Jeddah, Doha, Kuwait City, Baghdad.
What is the UTC offset for AST?
Arabia Standard Time (AST) is at UTC+03:00.
What should I know about the AST timezone?
None of the Gulf states on Arabia Standard Time observe daylight saving. AST is the same offset as Moscow Standard Time and East Africa Time.
When is it midnight in IRST, what time is it in Riyadh?
When it is 12:00 AM (midnight) in IRST (IRST), it is -0h 30m later in Riyadh (AST).
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