Tehran to Seoul Time
IRST to KST Converter — 9 AM IRST is 2:30 PM KST
Tehran is 5 hours and 30 minutes behind Seoul. Convert any time between Tehran (IRST/IRDT) and Seoul (KST) instantly.
Tehran
Iran
Seoul
South Korea
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Time Zone Comparison
Tehran to Seoul Time Conversion Table
| Tehran (IRST) | Seoul (KST) |
|---|---|
| 12:00 AM | 5:30 AM |
| 2:00 AM | 7:30 AM |
| 4:00 AM | 9:30 AM |
| 6:00 AM | 11:30 AM |
| 8:00 AM | 1:30 PM |
| 10:00 AM | 3:30 PM |
| 12:00 PM | 5:30 PM |
| 2:00 PM | 7:30 PM |
| 4:00 PM | 9:30 PM |
| 6:00 PM | 11:30 PM |
| 8:00 PM | 1:30 AM |
| 10:00 PM | 3:30 AM |
Tehran & Seoul — Business & Scheduling Guide
Tehran (Iran) is an important regional economy, with key industries in diverse sectors including services and trade. Seoul (South Korea) is a technology-driven economy known for rapid innovation, known for semiconductors, automotive, shipbuilding, and K-content. With a 5.5-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 Seoul
The 5.5-hour difference between Tehran and Seoul requires careful scheduling. The best overlap window is typically 2–4 hours when both cities are within working hours. Business hours typically follow a 9 AM–5 PM schedule. South Korean work culture is fast-paced with typical hours of 9 AM–6 PM, though recent reforms have reduced maximum weekly hours. Teams often designate specific "overlap hours" for real-time collaboration and use asynchronous communication (Slack, email, recorded video) for the rest of the day.
Daylight Saving Time Considerations
Tehran observes Daylight Saving Time (IRST/IRDT), but Seoul does not — it stays on KST year-round. This means the time difference between Tehran and Seoul changes by 1 hour when Tehran switches clocks. During Iran's summer, the gap is 4.5–6.5 hours instead of the standard 5.5 hours. Mark DST transition dates on your calendar to avoid missed meetings.
IRST to KST — Quick Reference
IRST (IRST/IRDT) stands for the timezone used in Tehran, Iran (UTC+3:30). KST (KST) is the timezone used in Seoul, South Korea (UTC+9). Tehran is 5 hours and 30 minutes behind Seoul.
To convert IRST to KST, add 5.5 hours to IRST time. For example, IRST 9:00 AM = KST 2:30 PM.
Key Facts
- •Time difference: Tehran (UTC+3:30) is 5 hours and 30 minutes behind Seoul (UTC+9).
- •Daylight Saving Time: Tehran observes DST (IRST/IRDT). Seoul does not observe DST (KST).
- •Regions: Tehran is located in Iran and uses the IRST/IRDT time zone. Seoul is located in South Korea and uses the KST time zone.
- •Best time to call: The best time to call between Tehran and Seoul is 9:00 AM to 11:00 AM in Tehran time, when both cities have overlapping standard working hours.
Frequently Asked Questions
What is the time difference between Tehran and Seoul?
Tehran is 5 hours and 30 minutes behind Seoul.
What time is it in Seoul when it's 9 AM in Tehran?
When it's 9:00 AM in Tehran, it is 2:30 PM in Seoul.
What time is 9 PM IRST in KST?
9 PM IRST (Tehran time) is 2:30 AM KST (Seoul 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 Seoul?
The best time to schedule a meeting is between 9:00 AM to 11:00 AM 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 KST?
IRST (IRST/IRDT) is the timezone for Tehran, Iran (UTC+3:30). KST (KST) is the timezone for Seoul, South Korea (UTC+9). Tehran is 5 hours and 30 minutes behind Seoul. Quick examples: 9 AM IRST = 2:30 PM KST, 12 PM IRST = 5:30 PM KST, 3 PM IRST = 8:30 PM KST, 6 PM IRST = 11:30 PM KST.
Is Tehran ahead of or behind Seoul?
Tehran is 5 hours 30 minutes behind Seoul. When it's noon in Tehran, it's 5:30 PM in Seoul.
Does Tehran or Seoul change clocks for Daylight Saving Time?
Yes, Tehran observes DST and switches between IRST/IRDT. Seoul does not observe DST — it stays on KST 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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