It turns out, Spongebob didn't make up Leif Erikson day in the episode below. Leif Erikson and the Vikings are said to have discovered America before Columbus. So, in 1925, President Coolidge recognized this fact. Then in 1963 John Blatnik, a US Representative introduced a bill to observe Leif Erikson Day. The bill was unanimously adopted in 1964. Every president since Lyndon B Johnson have made a proclamation of Leif Erikson Day every year on October 9th.
You heard it here first.
Do not forget to wish everybody a Happy Leif Erikson day this Saturday!