Joe's Lawn Care in Charlotte, NC is a cash basis taxpayer. Joe Martin, the sole proprietor, is considering delaying some of his December 2018 customer billings for lawn care into the next year, 2019. In addition, he is thinking about paying some of the bills in late December 2018, which he would ordinarily pay in January, 2019. This way, he claims he will have "less income and more expenses, so he will owe less in taxes." Is he correct in his way of thinking? Is this alright?