Convert IRST to CST — Time Difference Between Iran Standard Time and Costa Rica

How to Convert IRST to CST

Drag the slider on the IRST timeline to pick your time — the CST time updates instantly. You can also click the time display to type a specific hour or pick one from the 15-minute interval dropdown, and use the date picker to check a different day.

What Is the Time Difference Between IRST and CST?

Costa Rica (CST) is 9:30 hours behind Iran Standard Time (IRST). To convert, subtract 9:30 hours — for example, 9:00 AM IRST is 11:30 PM (previous day) CST.

IRST to CST Quick Reference

IRST to CST Meeting Planner

Use the color-coded table above to find overlapping work hours between Tehran and Costa Rica. Amber rows mark daytime hours — pick a slot that falls in amber on both sides for a meeting that works for everyone.

Why Trust This IRST to CST Converter?

Timezoney uses the IANA Time Zone Database — the same source that powers your phone and computer — so every conversion handles daylight saving transitions and half-hour offsets automatically.