The magnetic chemically peculiar (mCP) star CU Virginis is the most enigmatic star among upper main sequence stars. It is an unusually fast rotator showing strictly periodic light variations in all regions of the electromagnetic spectrum, as well as spectroscopic and spectropolarimetric changes. At the same time, it is also the first main-sequence radio pulsar. Exploiting information hidden in phase variations, we monitored the secular oscillation of the rotational period during the last 53 years. Applying our own phenomenological approach, we analyzed 37 975 individual photometric and spectroscopic measurements from 72 data sources and improved the O-C model. All the relevant observations indicate that the secular period variations can be well approximated by a 5th degree polynomial. The outer surface, “fastened” by the global magnetic field, seems to be stable for decades as shown by the constancy of the mutual location of different phase tracers on the stellar surface.