How Time Travelers Pass The Time

Manse Everard must approach Palermo on foot in 1137alpha so Karel Novak leaves him by timecycle in a nearby mountain ravine. Novak can wait indefinitely for Everard to return because he can travel elsewhere to eat and sleep and return within minutes. This is one of the practical applications of time travel. No doubt, there are others, e.g.:

 In Beyond the Barrier by Damon Knight, a couple depart to seek a time traveler stranded in the past a moment after seeing themselves return safely with him. Their child does not accompany them but is not left unattended. (Copied from here.)

I remembered that Knight had made some other subtle point about the implications of time travel but I had to find and reread the relevant passage to be reminded of what it was. Two time traveling aliens have brought Naismith to a large, abandoned spaceship where he has given them the slip. He wants to learn as much as he can by exploring the ship but not necessarily to evade the aliens indefinitely. Then, after two weeks of caution and solitude, he realizes:

"Suppose the aliens had begun to use the time machine to search for him as soon as they had found him missing. Almost certainly they would have begun by searching their own lounge and the corridor outside it, for a month or so into the future. If they had done that, and found him, there would never have been any necessity to search elsewhere in the ship. Accordingly, if Naismith was in fact going to be found in the alien's suite or near it, he could roam anywhere he pleased until that time, elsewhere in the ship, without any fear of discovery."
-Damon Knight, Beyond The Barrier (Feltham, Middlesex, 1978), p. 80.

Yes. Why didn't I think of that? Poul Anderson, the main subject of this blog, was a master of time travel subtlties. It is good to compare him with some of his peers.