In Vernor Vinge's A Deepness in the Sky, the Unix epoch is still used thousands of years in the future, but "programmer archaeologists" of the time mistakenly believe that was the date when humans first landed on the moon. They also measure time in kiloseconds and megaseconds because "day" or "week" don't mean much for interstellar travelers.

https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky#Interste...