The temperature dependence of the pitch in a planar oriented cholesteric layer has been examined and it is shown that, before the jump in the number of half-pitches in the sample changes by 1, the director orientation deviates from the alignment direction at the sample surface. The number of half-pitches changes into a noninteger number. This deviation angle depends on the strength of the anchoring at the surface and when the elastic constant K-22 is known, the anchoring energy can be determined.