Santiago is 5 hours behind Milan
Best overlap: 1:00 PM to 6:00 PM in Milan is 8:00 AM to 1:00 PM in Santiago.
Shoot for 1:00 PM to 6:00 PM in Milan; your Santiago colleagues will see that as 8:00 AM to 1:00 PM. Santiago is 5 hours behind Milan, so you've got a workable 5-hour overlap — ideal for a standing meeting around 1:00 PM in Milan (8:00 AM in Santiago).