World War II has a kind of temporal gravity. We are continually pulled back to it.
Recruits to Poul Anderson's Time Patrol identify themselves by name followed by place and year of recruitment, thus:
Manson Eeverard, New York, 1954;
Charles Whitcomb, London, 1947.
Despite that seven year difference, Everard and Whitcomb are members of the same Academy class which is recruited from the period 1850-2000 and which also includes a young physicist from 1972. Described as a girl, she must have been born post-War. Everard's and Whitcomb's dates of recruitment inform us that they had been in the War. In fact, Whitcomb had just been demobbed from the RAF. What better recruit to the Patrol? Except that his proximity to the War motivates him to commit a time crime: to try to prevent his fiancee's death in an air raid in 1944, just ten years before Everard's recruitment. The War is always close and even closer for Time Patrolmen.
When Everard becomes involved to help his friend, he loses any innocence that he might have retained after his first trip, in normal time, through World War II. At the very end of the opening story, "Time Patrol," Everard returns to his home base from London, 1944:
"Everard climbed weakly aboard the hopper. And when he got off again, a decade had passed." (Time Patrol, p. 53)
Of course a decade passes between 1944 and 1954 but the morals of the story are that:
Everard has now experienced time travel for real;
he feels as if he has aged ten years in a very short subjective span.