  This paper provides an elementary proof of the classical limit of the
Schr\"{o}dinger equation with WKB type initial data and over arbitrary long
finite time intervals. We use only the stationary phase method and the
Laptev-Sigal simple and elegant construction of a parametrix for
Schr\"{o}dinger type equations [A. Laptev, I. Sigal, Review of Math. Phys. 12
(2000), 749-766]. We also explain in detail how the phase shifts across
caustics obtained when using the Laptev-Sigal parametrix are related to the
Maslov index.
