1. Marco; a calendar year, accrual basis taxpayer; operates a restaurant as a sole proprietorship. His monthly electric bill for the restaurant runs from the 15th of the current month to the 14th of the subsequent month. He received his December electric bill for $650 on January 18, 2019. The bill included charges for December 15, 2018 through January 14, 2019. He accrued the entire bill in December 2018, which is how he has handled each monthly charge since opening the restaurant in 2017. When and how much can he deduct for the electricity bill?