Tehran to Riyadh Time
IRST to AST Converter — 9 AM IRST is 8:30 AM AST
Tehran is 0 hours and 30 minutes ahead of Riyadh. Convert any time between Tehran (IRST/IRDT) and Riyadh (AST) instantly.
Tehran
Iran
Riyadh
Saudi Arabia
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Time Zone Comparison
Tehran to Riyadh Time Conversion Table
| Tehran (IRST) | Riyadh (AST) |
|---|---|
| 12:00 AM | 11:30 PM |
| 2:00 AM | 1:30 AM |
| 4:00 AM | 3:30 AM |
| 6:00 AM | 5:30 AM |
| 8:00 AM | 7:30 AM |
| 10:00 AM | 9:30 AM |
| 12:00 PM | 11:30 AM |
| 2:00 PM | 1:30 PM |
| 4:00 PM | 3:30 PM |
| 6:00 PM | 5:30 PM |
| 8:00 PM | 7:30 PM |
| 10:00 PM | 9:30 PM |
Tehran & Riyadh — Business & Scheduling Guide
Tehran (Iran) is an important regional economy, with key industries in diverse sectors including services and trade. Riyadh (Saudi Arabia) is the largest economy in the Middle East, known for oil & gas, construction, finance, and tourism under Vision 2030. With a 0.5-hour time difference, professionals frequently schedule cross-border calls between these two cities for international trade, remote team collaboration, and client meetings.
Scheduling Meetings Between Tehran and Riyadh
With only a 0.5-hour gap, Tehran and Riyadh have generous overlapping work hours. Morning calls in the earlier time zone align well with mid-day in the other. Business hours typically follow a 9 AM–5 PM schedule. Saudi business hours typically run 9 AM–5 PM Sunday–Thursday, with business often conducted over meals. Most teams find that late morning to early afternoon offers the widest window for collaboration.
Daylight Saving Time Considerations
Tehran observes Daylight Saving Time (IRST/IRDT), but Riyadh does not — it stays on AST year-round. This means the time difference between Tehran and Riyadh changes by 1 hour when Tehran switches clocks. During Iran's summer, the gap is 0.5–1.5 hours instead of the standard 0.5 hours. Mark DST transition dates on your calendar to avoid missed meetings.
IRST to AST — Quick Reference
IRST (IRST/IRDT) stands for the timezone used in Tehran, Iran (UTC+3:30). AST (AST) is the timezone used in Riyadh, Saudi Arabia (UTC+3). Tehran is 0 hours and 30 minutes ahead of Riyadh.
To convert IRST to AST, subtract 0.5 hours from IRST time. For example, IRST 9:00 AM = AST 8:30 AM.
Key Facts
- •Time difference: Tehran (UTC+3:30) is 0 hours and 30 minutes ahead of Riyadh (UTC+3).
- •Daylight Saving Time: Tehran observes DST (IRST/IRDT). Riyadh does not observe DST (AST).
- •Regions: Tehran is located in Iran and uses the IRST/IRDT time zone. Riyadh is located in Saudi Arabia and uses the AST time zone.
- •Best time to call: The best time to call between Tehran and Riyadh is 10:00 AM to 4:00 PM in Tehran time, when both cities have overlapping standard working hours.
Frequently Asked Questions
What is the time difference between Tehran and Riyadh?
Tehran is 0 hours and 30 minutes ahead of Riyadh.
What time is it in Riyadh when it's 9 AM in Tehran?
When it's 9:00 AM in Tehran, it is 8:30 AM in Riyadh.
What time is 9 PM IRST in AST?
9 PM IRST (Tehran time) is 8:30 PM AST (Riyadh time). This is a common time people check when scheduling evening calls across these two time zones.
When is the best time to schedule a meeting between Tehran and Riyadh?
The best time to schedule a meeting is between 10:00 AM to 4:00 PM in Tehran time, when both cities are within standard working hours (9 AM – 5 PM). This gives you the maximum overlap window for real-time collaboration.
How do I convert IRST to AST?
IRST (IRST/IRDT) is the timezone for Tehran, Iran (UTC+3:30). AST (AST) is the timezone for Riyadh, Saudi Arabia (UTC+3). Tehran is 0 hours and 30 minutes ahead of Riyadh. Quick examples: 9 AM IRST = 8:30 AM AST, 12 PM IRST = 11:30 AM AST, 3 PM IRST = 2:30 PM AST, 6 PM IRST = 5:30 PM AST.
Is Tehran ahead of or behind Riyadh?
Tehran is 30 minutes ahead of Riyadh. When it's noon in Tehran, it's 11:30 AM in Riyadh.
Does Tehran or Riyadh change clocks for Daylight Saving Time?
Yes, Tehran observes DST and switches between IRST/IRDT. Riyadh does not observe DST — it stays on AST year-round. Because only one city observes DST, the time difference shifts by 1 hour during transition periods (typically March/April and October/November).
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