Overlapping Real And Fictional Chronologies

"Life-Line" by Robert Heinlein:

was published in Astounding, August 1939;
was Heinlein's first published story;
is the opening story of his Future History;
is set in 1951.

"Un-Man" by Poul Anderson:

was published in Astounding, January 1953;
is the second story in Anderson's Psychotechnic History;
but was published earlier than the opening story ("Marius," Astounding, June 1957);
was published two years after "Life-Line" is set;
is set in 2004, according to the published Chronology of the Psychotechnic Series.

Worth noting:

"Life-Line"'s publication date places it before the watershed twentieth century event of World War II;
despite different series by different authors, there is literary continuity both in Astounding and in the publication of future histories;
much of the fictional future has become past;
we are now well over half a century past the beginning of the Future History;
however, Future History Vol III is Revolt In 2100;
we still appreciate past futures.