how often does the train travel to and from Philadelphia

Rush hour is every hour. No service on sundays which sucks. Saturday follows holiday hours. When it rains and windy expect delays, and days like that if you can drive into Center City if you work there. Check septa.org or download their app where will show you real-time routes.

http://www.septa.org/schedules/rail/w/PAO_0.html

You need to check Septa.com. The schedule varies. Nothing on Sunday.