This was Howel Davis, whose adventures are related at length in Johnson's History of the Pirates, chap. ix.
The History of the Pirates gives the date as 19th of July. This book gives an interesting account of Kennedy, pp. 178-81.
The Life of MATTHEW CLARK, a Footpad and Murderer
Perhaps there is nothing to which we may more justly attribute those numerous executions which so disgrace our country, than the false notions which the meaner sort, especially, imbibe in their youth as to love and women. This unhappy person, Matthew Clark, of whom we are now to speak, was a most remarkable instance of the truth of this observation. He was born at St. Albans, of parents in but mean circumstances, who thought they had provided very well for their son when they had procured his admission into the family of a neighbouring gentleman, equally distinguished by the greatness of his merit and fortune.