Question: When did the first episode of phineas and ferb come out?
Disambiguated questions and answers: question: When did the first one-episode preview of phineas and ferb come out?
When did the first episode of the phineas and ferb series officially come out?
answer: August 17, 2007
February 1, 2008
Natural Questions answer: August 17 , 2007 (from the Wikipedia article "Phineas and Ferb")