Melachim Alef 12:32-33

Orthodox Jewish Bible

³² And Yarov`am ordained a chag in the eighth month, on the fifteenth day of the month, like unto the chag that is in Yehudah, and he offered upon the mizbe’ach. So did he in Beit-El, sacrificing unto the agalim (calves) that he had made; and he installed in Beit-El the kohanim of the [idolatrous] high places which he had made.

³³ So he offered upon the mizbe’ach which he had made in Beit-El the fifteenth day of the eighth month, even in the month which he had devised of his own lev; and ordained a chag unto the Bnei Yisroel; and he offered upon the mizbe’ach, and burned ketoret.