Although clocks and watches are only simple inventions of humanity used to quantify time, people often attach extraordinary significance to them. Some people may set their clock or watch ten minutes back as an excuse to sleep in, while others may set it ten minutes ahead to be sure to wake up on time. Sometimes it can seem as if it controls time, rather than the other way around.
In the year 1944, Lindsay Bradley is drafted into the second world war. As a token of their appreciation, his company presents him with a gold watch. Lindsay soon discovers that by setting his watch forward or backward he can actually control time within a twelve hour period. He comes to be afraid of it, using its power only when necessary. He wonders if, should the watch ever be broken or not be properly wound, time itself would come to a halt.
A fascinating study of human fears and desires, "It's Later Than You Think" uses time travel as a device to show the disorientation of the young man heading off to war. Later, after he returns home again, the watch is stuck two hours ahead of where it should be. This illustrates that the war has taken something from him -- that a part of his life is missing even after he comes home.
I set the watch back two hours, and all the tanks and guns disappeared.