Tehran to San Juan Time
IRST to AST Converter — 9 AM IRST is 1:30 AM AST
Tehran is 7 hours and 30 minutes ahead of San Juan. Convert any time between Tehran (IRST/IRDT) and San Juan (AST) instantly.
Tehran
Iran
San Juan
Puerto Rico
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Time Zone Comparison
Tehran to San Juan Time Conversion Table
| Tehran (IRST) | San Juan (AST) |
|---|---|
| 12:00 AM | 4:30 PM |
| 2:00 AM | 6:30 PM |
| 4:00 AM | 8:30 PM |
| 6:00 AM | 10:30 PM |
| 8:00 AM | 12:30 AM |
| 10:00 AM | 2:30 AM |
| 12:00 PM | 4:30 AM |
| 2:00 PM | 6:30 AM |
| 4:00 PM | 8:30 AM |
| 6:00 PM | 10:30 AM |
| 8:00 PM | 12:30 PM |
| 10:00 PM | 2:30 PM |
Tehran & San Juan — Business & Scheduling Guide
Tehran (Iran) is one of the Middle East's largest economies with a young population, with key industries in oil and gas, petrochemicals, automotive, and agriculture. San Juan (Puerto Rico) is a US territory with pharmaceutical and tech manufacturing, known for pharmaceuticals, medical devices, electronics, and tourism. With a 7.5-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 San Juan
The 7.5-hour difference between Tehran and San Juan requires careful scheduling. The best overlap window is typically 2–4 hours when both cities are within working hours. Iranian business hours are typically 8 AM–4 PM Saturday–Wednesday, with Thursday as a half-day and Friday off. Puerto Rican business hours are typically 8 AM–5 PM, with a bilingual (English/Spanish) workforce. 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 San Juan does not — it stays on AST year-round. This means the time difference between Tehran and San Juan changes by 1 hour when Tehran switches clocks. During Iran's summer, the gap is 6.5–8.5 hours instead of the standard 7.5 hours. Mark DST transition dates on your calendar to avoid missed meetings.
Collaboration Tools & Workflow
With a 7.5-hour time difference, Tehran and San Juan teams operate in a near "follow-the-sun" model. When one team logs off, the other picks up — enabling near-24-hour productivity on shared projects. The key challenge is handoff quality: teams should document decisions in shared tools (Notion, Confluence, Linear), record video updates with Loom, and write thorough pull request descriptions. Weekly all-hands meetings require someone to take an early morning or late evening call, so the best practice is to rotate this burden fairly between Tehran and San Juan.
Remote Work Between Tehran & San Juan
Tehran, a key city in Iran, and San Juan, a key city in Puerto Rico, represent a common corridor for distributed teams navigating a 7.5-hour time difference. Remote workers and freelancers operating between these cities should plan their day around the overlap window — typically the late morning for one city and early morning or late afternoon for the other. Using a world clock widget, setting Slack status with local time, and blocking "no-meeting" deep work hours outside the overlap are essential practices for productive cross-timezone remote collaboration between Tehran and San Juan.
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 San Juan, Puerto Rico (UTC-4). Tehran is 7 hours and 30 minutes ahead of San Juan.
To convert IRST to AST, subtract 7.5 hours from IRST time. For example, IRST 9:00 AM = AST 1:30 AM.
Key Facts
- •Time difference: Tehran (UTC+3:30) is 7 hours and 30 minutes ahead of San Juan (UTC-4).
- •Daylight Saving Time: Tehran observes DST (IRST/IRDT). San Juan does not observe DST (AST).
- •Regions: Tehran is located in Iran and uses the IRST/IRDT time zone. San Juan is located in Puerto Rico and uses the AST time zone.
- •Best time to call: There are no overlapping standard work hours (9 AM - 5 PM) between these two cities.
Frequently Asked Questions
What is the time difference between Tehran and San Juan?
Tehran is 7 hours and 30 minutes ahead of San Juan.
What time is it in San Juan when it's 9 AM in Tehran?
When it's 9:00 AM in Tehran, it is 1:30 AM in San Juan.
What time is 9 PM IRST in AST?
9 PM IRST (Tehran time) is 1:30 PM AST (San Juan 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 San Juan?
There are no overlapping standard work hours (9 AM - 5 PM) between these two cities.
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 San Juan, Puerto Rico (UTC-4). Tehran is 7 hours and 30 minutes ahead of San Juan. Quick examples: 9 AM IRST = 1:30 AM AST, 12 PM IRST = 4:30 AM AST, 3 PM IRST = 7:30 AM AST, 6 PM IRST = 10:30 AM AST.
Is Tehran ahead of or behind San Juan?
Tehran is 7 hours 30 minutes ahead of San Juan. When it's noon in Tehran, it's 4:30 AM in San Juan.
Does Tehran or San Juan change clocks for Daylight Saving Time?
Yes, Tehran observes DST and switches between IRST/IRDT. San Juan 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).
What time is noon in Tehran in San Juan time?
When it is 12:00 PM (noon) in Tehran (IRST), it is 4:30 AM in San Juan (AST). This is often a popular time for scheduling lunch-hour calls across the Tehran–San Juan corridor.
What are the overlapping work hours between Tehran and San Juan?
There are no overlapping standard work hours (9 AM - 5 PM) between these two cities. This makes real-time collaboration challenging — most teams between Tehran and San Juan rely on asynchronous communication (Slack, Loom, email) and rotate meeting times to share the inconvenience fairly.
What timezone is Tehran in?
Tehran is in the IRST/IRDT time zone (UTC+3:30). It is located in Iran. Tehran observes Daylight Saving Time, switching between IRST/IRDT.
What timezone is San Juan in?
San Juan is in the AST time zone (UTC-4). It is located in Puerto Rico. San Juan does not observe Daylight Saving Time.
How do I schedule a call between Tehran and San Juan?
Since there are no standard overlapping work hours between Tehran and San Juan, the best approach is to alternate meeting times. One week, the Tehran team takes an early/late call; the next week, the San Juan team does. Use a scheduling tool like Calendly or Google Calendar with multiple time zones enabled to find the least disruptive time for both sides.
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