Originally Posted by GNRMatt

I wouldn't risk the 65 minute connection. Even a slight delay can put your ZRH flight at risk. If it's important to get to Switzerland on Sunday, I'd say 65 minutes is not a good idea.

Also, as another option, since DCA isn't too far, perhaps consider just dropping the DCA-PHL leg (although this may re-price your ticket), and driving up to PHL. Or even looking at switching to leaving from BWI.