David [was] thirty years old when he began to reign, [and] he reigned forty years. (5:4)

In Hebron he reigned over Judah seven years and six months: and in Jerusalem he reigned thirty and three years over all Israel and Judah. (5:5)

--1 Chronicles--

And he died in a good old age, full of days, riches, and honour: and Solomon his son reigned in his stead. (29:28)