Day One is the eighth episode of Season 4 of Lloyd in Space, which was first broadcast on February 13, 2004.
Eddie reminds Lloyd about an incident from 1st grade that led to him becoming unpopular during his future school years. When Douglas gives him a traveling time communicating watch which will able to take him to any time he wants, Lloyd then goes back to the day he first went to school in Intrepidville to stop his little self from tripping over Rodney's foot and ruining Brittany's picture and he becomes popular in the present. However, Lloyd also realizes that him becoming popular meant that he never made friends with Eddie, Douglas, and Kurt, whom he feels sorry for upon finding out how poorly they've turned out without befriending him, prompting him to go back and restore the balance of time and his former unpopular life.
- This episode reveals that Lloyd, Eddie, Douglas, Kurt, Brittany, Rodney, Megan, Violet, Elmer, Marcus, Jake, Mendel, Geneveeve, Lou, Benny, Grace, and almost every other recurring or minor character of Luna Vista have known each other since as far back as elementary school. This also more or less revelates how much of an impacting role Lloyd has provided for Eddie, Douglas, and Kurt in being friends with them.
- This episode marks Nora and Francine's final appearances on the show. This is also the last episode where Megan speaks.
- This episode somewhat contradicts to Love Beam Number 9 in which it is said that Lloyd and Brittany knew each other since they were both 5 years old, meaning that they would have been as young as Pre-K or kindergarten. Here though, it is shown that they first met during 1st grade, meaning they would have been as young as 6-7 years.
- When Young Lloyd first introduces himself, he just mentions his mother and not his father. Therefore, it wouldn't make sense for Francine to exist, since if Francine was born, their father should've been around when Lloyd was an only child.
- Clancy Brown as Officer Frank Horton
- Rachel Crane as Megan Uno
- Bill Fagerbakke as Kurt
- Brian George as Station
- Pamela Hayden as Douglas McNoggin
- Nicolette Little as Francine Nebulon
- Anndi McAfee as Brittany Boviak
- Courtland Mead as Lloyd Nebulon
- Justin Shenkarow as Eddie Horton
- Warren Sroka as Rodney
- April Winchell as Nora Nebulon