SB-129 is an episode from season 1. In this episode Squidward time travels to the past and the future.
The episode begins with Squidward opening up his window to play his clarinet. However, SpongeBob's alarm clock goes off right at that moment causing the clarinet to get lodged into Squidward's throat. SpongeBob asks Squidward if he wants to go jellyfishing, and takes Squidward's inaudible protests as a "yes". After finally dislodging the clarinet, Squidward answers the knocking of his door to find SpongeBob and Patrick waiting for him. When Squidward refuses to come out, they believe it is because he is preparing to go jellyfishing and repeatedly ask him if he is ready. Squidward asks why SpongeBob is not working, and SpongeBob replies sadly saying that the Krusty Krab is closed on Sunday. Squidward decides to hide from SpongeBob and Patrick in the Krusty Krab since it is closed. Squidward locks himself in the freezer and is frozen. He wakes up 2000 years later, where SpongeTron encounters a frozen Squidward. Using a laser, SpongeTron unthaws Squidward. Squidward asks if SpongeTron is SpongeBob, but SpongeTron informs Squidward he is in the future. Horrified, Squidward asks if there is a way back to his own timeline, SpongeTron directs him to the time machine after having accidentally directed Squidward to the can opener.
The time machine takes him to the distant past. Squidward decides that it would be a good place to play his clarinet in peace. However, Squidward soon realizes he is being watched and encounters the Primitive Sponge and Primitive Star. After teaching them how to jellyfish, Squidward goes to play his clarinet, but the sound causes the primitives to start chasing after Squidward. Squidward gets back to the time machine and breaks it, teleporting him to literal Nowhere. Squidward is glad to have somewhere he can be alone, but the complete solitude proves too much for him to bear. After searching all across the void, he finally crashes into the time machine and bangs the controls, wishing for it to take him back, even if he has to see SpongeBob. Back in the present, Squidward encounters SpongeBob and Patrick, asking him if he still wants to jellyfish. Squidward refuses and demands to know who invented jellyfishing, SpongeBob then happily says that Squidward invented it.