Seoul to Tehran Time
KST to IRST Converter — 9 AM KST is 3:30 AM IRST
Seoul is 5 hours and 30 minutes ahead of Tehran. Convert any time between Seoul (KST) and Tehran (IRST/IRDT) instantly.
Seoul
South Korea
Tehran
Iran
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Time Zone Comparison
Seoul to Tehran Time Conversion Table
| Seoul (KST) | Tehran (IRST) |
|---|---|
| 12:00 AM | 6:30 PM |
| 2:00 AM | 8:30 PM |
| 4:00 AM | 10:30 PM |
| 6:00 AM | 12:30 AM |
| 8:00 AM | 2:30 AM |
| 10:00 AM | 4:30 AM |
| 12:00 PM | 6:30 AM |
| 2:00 PM | 8:30 AM |
| 4:00 PM | 10:30 AM |
| 6:00 PM | 12:30 PM |
| 8:00 PM | 2:30 PM |
| 10:00 PM | 4:30 PM |
Seoul & Tehran — Business & Scheduling Guide
Seoul (South Korea) is a technology-driven economy known for rapid innovation, with key industries in semiconductors, automotive, shipbuilding, and K-content. Tehran (Iran) is an important regional economy, known for diverse sectors including services and trade. 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 Seoul and Tehran
The 5.5-hour difference between Seoul and Tehran requires careful scheduling. The best overlap window is typically 2–4 hours when both cities are within working hours. South Korean work culture is fast-paced with typical hours of 9 AM–6 PM, though recent reforms have reduced maximum weekly hours. Business hours typically follow a 9 AM–5 PM schedule. 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), while Seoul stays on KST year-round. When Tehran switches to daylight time, the effective time difference shifts by 1 hour. This typically happens in spring and fall, and the exact dates vary by country. If you have recurring cross-timezone meetings, recalculate the schedule after each DST transition.
KST to IRST — Quick Reference
KST (KST) stands for the timezone used in Seoul, South Korea (UTC+9). IRST (IRST/IRDT) is the timezone used in Tehran, Iran (UTC+3:30). Seoul is 5 hours and 30 minutes ahead of Tehran.
To convert KST to IRST, subtract 5.5 hours from KST time. For example, KST 9:00 AM = IRST 3:30 AM.
Key Facts
- •Time difference: Seoul (UTC+9) is 5 hours and 30 minutes ahead of Tehran (UTC+3:30).
- •Daylight Saving Time: Seoul does not observe DST (KST). Tehran observes DST (IRST/IRDT).
- •Regions: Seoul is located in South Korea and uses the KST time zone. Tehran is located in Iran and uses the IRST/IRDT time zone.
- •Best time to call: The best time to call between Seoul and Tehran is 3:00 PM to 4:00 PM in Seoul time, when both cities have overlapping standard working hours.
Frequently Asked Questions
What is the time difference between Seoul and Tehran?
Seoul is 5 hours and 30 minutes ahead of Tehran.
What time is it in Tehran when it's 9 AM in Seoul?
When it's 9:00 AM in Seoul, it is 3:30 AM in Tehran.
What time is 9 PM KST in IRST?
9 PM KST (Seoul time) is 3:30 PM IRST (Tehran 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 Seoul and Tehran?
The best time to schedule a meeting is between 3:00 PM to 4:00 PM in Seoul 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 KST to IRST?
KST (KST) is the timezone for Seoul, South Korea (UTC+9). IRST (IRST/IRDT) is the timezone for Tehran, Iran (UTC+3:30). Seoul is 5 hours and 30 minutes ahead of Tehran. Quick examples: 9 AM KST = 3:30 AM IRST, 12 PM KST = 6:30 AM IRST, 3 PM KST = 9:30 AM IRST, 6 PM KST = 12:30 PM IRST.
Is Seoul ahead of or behind Tehran?
Seoul is 5 hours 30 minutes ahead of Tehran. When it's noon in Seoul, it's 6:30 AM in Tehran.
Does Seoul or Tehran change clocks for Daylight Saving Time?
No, Seoul does not observe DST — it stays on KST year-round. Tehran observes DST and switches between IRST/IRDT. 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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