Mister Roberts... and Dave--a curious inscription

Thomas Heggens' Mister Roberts was published by Houghton Mifflin in 1946. The story was set on a US Navy cargo ship toward the end of World War II, based on the author's experiences during the war in the South Pacific.

The title character, Mister Roberts, was a junior officer who had the respect of his men and disdain for the captain, who had little regard for the crew. Roberts fought the captain for a transfer to the front lines to see some action before the war ended, eventually got his wish, and was killed in action.

I have a copy of the novel with the following curious gift inscription:

Dave,

Here in detail are episodes in the lives of the men with whom you served on that Sunday afternoon of 8th April 1951.

And that has left me wanting for more detail. Who was Dave and what happened on April 8, 1951? Did Dave just serve one day with "these men?" On a ship? And at war? Or was this a reference to particular event during the course of a longer tour of duty by Dave?

I can find nothing of significance occurring on April 8, 1951 to relate to the characters and setting of Mister Roberts. The US military was fighting a war in Korea and General Douglas MacArthur was about to lose his command. But the specific date of April 8, 1951 is a riddle.

I'm guessing a good number of veterans could relate to the characters and situations in this book, Dave and the author of the inscription being just two examples of that sentiment. I'm assuming the inscription's author could relate on some level to have assumed that Dave would also. And the inscription became a device for introducing the book and evidently some wartime memories for its recipient.

The inscription itself is not dated, so there's no way of knowing when this used copy of the book was presented to Dave. If it were 1955 or later, no doubt Dave had heard of Mister Roberts the movie, if not the book. After being adapted as a play in 1948 Mister Roberts found new life in yet another medium as a 1955 film starring Henry Fonda, James Cagney, William Powell, and Jack Lemmon. The film was nominated for Best Picture and Lemmon won the Oscar for Best Supporting Actor.