2100 In Three Histories

"By Twenty-one hundred A.D., the Jovial colonists found themselves without a sponsor, no ties to Earth, almost completely cut off by the expense of travel to their system."
-Poul Anderson, The Snows Of Ganymede (New York, 1958), Chapter 3, p. 15.

Volume III of Robert Heinlein's Future History is Revolt In 2100 although the Time Chart puts "If This Goes On -," about the Second American Revolution, before 2075. "The Barrier," which encloses the post-Revolutionary Coventry, is dated 2100.

In James Blish's Chronology of Cities In Flight:

2105 Fall of the West (an agreed arbitrary date).

Very "arbitrary." Why not just cite the round number, 2100?

Anderson has colonials in the Jovian System whereas Blish has:

2021 Escape of the "Colonials" from the Jovian system.

Robert Heinlein, The Man Who Sold The Moon (London, 1963), pp. 6-7.
James Blish, Year 2018! (London, 1964), pp. 157-159.