It has been argued that one of Jeroboam's sins was that he added an extra Elul to the calendar, causing the holiday of Sukkot to fall out in the eighth month instead of the seventh month. See Klein, Reuven Chaim (2018). "The Leap-Month Fabricated by Jeroboam"(PDF). Jewish Bible Quarterly. 46 (1): 13–18. doi:10.17613/M6P843V9D.
It has been argued that one of Jeroboam's sins was that he added an extra Elul to the calendar, causing the holiday of Sukkot to fall out in the eighth month instead of the seventh month. See Klein, Reuven Chaim (2018). "The Leap-Month Fabricated by Jeroboam"(PDF). Jewish Bible Quarterly. 46 (1): 13–18. doi:10.17613/M6P843V9D.