  In this paper we describe a simple conceptual problem, regarding the actual
position of the Sun at sunset or sunrise. Although this problem can be easily
explained in terms of rotating frames of references and standard Coriolis
Effect, it is sometimes misunderstood by students and even by some physics
textbooks. We also present a simple experimental activity which can be used as
a demonstration of this peculiar kinematical effect in general physics courses,
or become part of laboratory activities.
