Phil and Pim have been fighting all week. Lloyd and Barbara couldn't take it any longer so he called for a Versa Day. For one school day Phil and Pim have to switch lives. Meanwhile Lloyd wants to get Curtis a job....if only he could find a place that will hire him.

Phil and Keely are on a virtu-date and the robot waiter starts flirting with Keely and Phil is jealous.

Phil and Keely have a huge test in Mr. Messerschmitt's class, but take advantage of The Giggle. Phil and Keely, then, both fail the test. So Phil tries to make it up to Keely. Meanwhile, Pim goes to an R-rated movie and brings curtis as her parent.

Mr. Hackett moves in next door and the Diffys invite him for dinner. Pim tries to sell the house.

When Tia moves away, Keely gets Phil into doing everything that she would normally do. So Phil hooks Keely up with the new girl.

Keely finally gets the courage to ask Phil to the dance. Phil agrees to go and Keely walks away as students file past. The students clear and both Keely and Phil see the other doing a happy dance. Later, Phil's dad, Lloyd, tells the family that he has fixed the time machine and they are leaving the next day. Phil has to break his date to a crushed Keely. After Phil tells Keely he is leaving Lloyd breaks the time machine. Phil tells Keely he can now go to the dance with her but she already has another date, Owen. Phil is crushed and asks Via to the dance. At the dance Via and Owen help get Phil and Keely together.

Mr. Messerschmitt insists his students take the Career Placement Test. However, Phil doesn't know what he wants to do and doesn't want to be trapped in a job for which is not suited.

Lloyd realizes that Pickford High School's time capsule is the key to returning the Diffy's to the future, he tells Phil to warn them from taking their time travel vaction in the year 2121.

Phil replaces Curtis as field trip chaperone when Mr. Hackett is too ill to escort their class to the museum. Phil locates a part from the time machine during a class trip to the museum.

When Phil & Keely baby-sit Nathan, the trouble-making nephew of Mr. Messerschmitt, they get more than they bargained for, so they use the New-Ager, a device that changes one's behavior. But things go hay-wire, leaving Nathan to act like an old man, while Phil is acting like a little boy. Now it's up to Keely to solve the problem before Mr. Messerschmitt and Phil's dad get home. But her only salvation, Pim, is too busy using the Wizrd to create and then sell the latest school project.

Phil uses future knowledge to solve one of Mr. Hackett's seemingly impossible math problems, but Keely inadvertently blurts out the answer and is promptly upgraded to advanced math class. Rather than have Mr. Hackett even more suspicious of his family, Phil helps Keely continue to look smart among the other genius students - while Keely teaches her new classmates to navigate the shopping mall. After Candida pulls a static electricity trick on her, Pim shuffles her way to find the best method for acquiring energy.

Pim abuses her power when she becomes principal for the day.

Phil is growing tired of everyone going into his room without his permission. He wants privacy and he isn't getting that from his room. When Lloyd stores tools from the Time Machine in Phil's room that shouldn't be next to each other, it ends up blowing the floor out and Phil has to live somewhere else. He chooses the garage and shares it with Curtis. But when Curtis is sick of Phil he decides to fix Phil's room and live there instead.

Phil makes a fool out of himself when he gets a question wrong in history and everyone laughs at him. It seems in the future they cloned Abraham Lincoln and Phil forgetting that he was in the present answered that Lincoln went down known as Stinkin Lincoln. Phil is angered by coming up with another excuse for why he said what he said. He feels like he is going to burst so he tells everyone his secret.

When Christmas Eve rolls around, Phil tells the story of when his family first came to Pickford and how he met Keely. Lloyd also decides to tell the story of how they got the house.

Keely tries to get together two people and it backfires on Phil. Pim becomes a "psychic" and fools Mr. Hackett.

When no one watches Keely's investigative reports show Pim comes to the resuce by offering to help make her popular amongst her viewers again but Keely realizes that Pim is just abusing her to make money and goes back to making "real news" with Phil.

It's Keely's birthday and Phil wants to give her the best birthday she has ever had. Last year he had forgotten her birthday so he wanted to go all out with her present this year. Phil's plans for the perfect outing are crushed when Lloyd takes out all the batteries to the future gadgets because it will get him "one step closer to fixing the time machine". Meanwhile Pim meets a fellow prankster and even has a crush on him.

The Diffy's catch a futuristic disease called greenemia which causes them to turn green and act completely opposite to how they usually act.

Phil loses the wizard and to his suprise he finds that Mr. Hackett has it. Now Phil is on a mission to get the wizard back. Will Mr. Hackett find out Phil is from the future?

Phil unwittingly prevents his great great grandfather from meeting his great great grandmother, thus causing a chain reaction in which he and his family are erased from existence.

Phil and Keely finally become a couple. Though Lloyd has all of a sudden fixed the time machine, now it's time for the Diffys to head back home. It's Keely's worst nightmare when she realizes Phil is leaving for real.