The Day of Firsts was a special 7-hour New Year's Day marathon that aired on Cartoon Network on January 1, 2005 from 12:00 PM to 7:00 PM. The marathon was meant to celebrate New Year's Day and featured very first episodes of the network's programming. Also, the marathon was hosted by Mr. Baby and Baby from Cartoon Network's Fridays.
- 12:00 PM - Ozzy & Drix
- 12:30 PM - The Powerpuff Girls
- 1:00 PM - Foster's Home for Imaginary Friends
- 1:30 PM - Foster's Home for Imaginary Friends
- 2:00 PM - Foster's Home for Imaginary Friends
- 2:30 PM - Hi Hi Puffy AmiYumi
- 3:00 PM - Evil Con Carne
- 3:30 PM - The Grim Adventures of Billy & Mandy
- 4:00 PM - Ed, Edd n Eddy
- 4:30 PM - Codename: Kids Next Door
- 5:00 PM - Atomic Betty
- 5:30 PM - Totally Spies!
- 6:00 PM - Teen Titans
- 6:30 PM - Static Shock