Most Cepheids are massive stars which evolve rather quickly compared to low-mass stars. One way of studying this evolution is by tracking changes in the pulsation period as shown with epochs of maxima fitted to an O-C diagram. Members of Variable Stars South and its predecessors have been active in this area. This poster shows the methods of doing that from the determination of mean light curves, the fitting of seasonal measures to these and the results. Some interesting stars are examined in detail.