Belfast City Council residents' magazine and John F Kennedy's biography by Whitehouse confirms C S Lewis and John F Kennedy both died on the same day.
As per Belfast City Council residents' magazine, C S Lewis was a British author who was born on 29 November 1898 in Belfast. One of his most popular accomplishments includes a novel called 'The Chronicles of Narnia'. He died on 22 November 1963 at the age of 64. (Page number - 19)