Rotational modulation due to dark spots co-rotating with the stellar surface allows us to constrain rotation and magnetic properties of solar-like stars. The long-term observations collected by \kep\ (and those that will be collected by PLATO) are preferred for a better characterization of magnetic activity. In this work, we investigate the temporal variability of the photometric magnetic activity proxy Sph, as well as the characteristic timescale of active-regions in solar-like stars.