They are not related; in fact, "Kaye" is a pseudonym for both men. Danny's real name at birth was David Daniel Kaminski, and Thorsten's real last name is Kieselbach.
Sammy Kaye was born on March 13, 1910.
Danny Kaye was born on January 18, 1913.
Danny Kaye was born on January 18, 1913 and died on March 3, 1987. Danny Kaye would have been 74 years old at the time of death or 99 years old today.