March Toon Mania was a US marathon of Nicktoons that would take place in March.
Every year in March, Nick would present special marathons of various Nicktoons, as well as expanded coverage of Nicktoon programming during the day. One by-product of March Toon Mania is Nick's weekend schedule, which consisted of double episodes of Nicktoons in the morning, plus all day Nicktoons on Saturday. Nick was so pleased with the ratings (especially with SpongeBob beating Pokemon in the ratings), Nick made the weekend schedule permament, after March 2000. The block has gone missing since.