In the opening credits of the film, we learn (by viewing his passport) that Clark was born in 1945 on the day before THIS HISTORIC WWII EVENT. (edited at 10:41 am, April 17, 2016 (CDT))
Original question: In the opening credits of the film, we learn (by viewing his passport) that Clark was born in 1945 on the same day as THIS HISTORIC WWII EVENT.
The bombing of Nagasaki