Delhi is 0.5 hours ahead of Islamabad
Best overlap: 8:30 AM to 5:30 PM in Islamabad is 9:00 AM to 6:00 PM in Delhi.
Your shared working hours run 8:30 AM to 5:30 PM in Islamabad (9:00 AM to 6:00 PM in Delhi). The 0.5-hour gap barely gets in the way — you've got 9 hours of overlap, so pick whatever time fits the agenda.