Islamabad is 5 hours ahead of Reykjavik
Best overlap: 8:00 AM to 1:00 PM in Reykjavik is 1:00 PM to 6:00 PM in Islamabad.
The overlap falls at 8:00 AM to 1:00 PM in Reykjavik, or 1:00 PM to 6:00 PM if you're in Islamabad. Roughly 5 hours of common time means scheduling is manageable; just avoid the very edges of the window.