Madrid is 6 hours ahead of Philadelphia
Best overlap: 8:00 AM to 12:00 PM in Philadelphia is 2:00 PM to 6:00 PM in Madrid.
The sweet spot is 8:00 AM to 12:00 PM Philadelphia time, matching 2:00 PM to 6:00 PM in Madrid. You've got a decent 4-hour window. Set a recurring time near 8:00 AM in Philadelphia (2:00 PM in Madrid) and stick to it.