1 Kings 12:32-33

³²And Jerobo'am appointed a feast on the fifteenth day of the eighth month like the feast that was in Judah, and he offered sacrifices upon the altar; so he did in Bethel, sacrificing to the calves that he had made. And he placed in Bethel the priests of the high places that he had made. ³³He went up to the altar which he had made in Bethel on the fifteenth day in the eighth month, in the month which he had devised of his own heart; and he ordained a feast for the people of Israel, and went up to the altar to burn incense.