It's About Time! (Part 1 & 2) - S1-E21
Other mistake: Near the end of the episode after they get back, when the camera zooms in on Phineas and Isabella, Isabella's face is gone - only her eyes remain, but after the camera zooms out her face is back.
Other mistake: The small door Candace enters at the beginning leads to the living room when really, it should be the kitchen. This error was not fixed in "Rollercoaster: The Musical."
Operation Crumb Cake/Mandace - S4-E21
Other mistake: When the reverse-inator zaps Phineas, and he takes apart the sculpture, it is impossible that he took down the whole thing alone, because he didn't build it alone.





Answer: And Bart Simpson should be about 40 by now. Cartoon characters don't age in real time. And are you really counting summer vacation days in a show about children who build spaceships and a platypus who's a secret agent?
Brian Katcher