Tehran is 7.5 hours ahead of Philadelphia
Best overlap: 8:00 AM to 11:00 AM in Philadelphia is 3:30 PM to 6:30 PM in Tehran.
Target 8:00 AM to 11:00 AM in Philadelphia, which lands at 3:30 PM to 6:30 PM for the Tehran side. Since Tehran is 7.5 hours ahead of Philadelphia, the workdays overlap by around 3 hours; 8:00 AM in Philadelphia (3:30 PM in Tehran) makes a reliable recurring slot. Don't be caught out by clock changes — Philadelphia observes daylight saving and Tehran doesn't, so the offset varies by an hour through the year.