An astronomer is on an expedition to Darkest Africa to observe a total eclipse of the sun, which will only be observable there, when he's captured by cannibals.
The eclipse is due the next day around noon. To gain his freedom he plans to pose as a god and threaten to extinguish the sun if he's not released, but the timing has to be just right. So, in the few words of the cannibals' primitive tongue that he knows, he asks his guard what time they plan to kill him.
The guard's answer is, "Tradition has it that captives are to be killed when the sun reaches the highest point in the sky on the day after their capture so that they may be cooked and ready to be served for the evening meal."
"Great," the astronomer replies.
The guard continues, though, "But because everyone's so excited about it, in your case we're going to wait until after the eclipse."