  We employed recently computed evolutionary white-dwarf models with helium
cores, supplemented by heavier models with carbon-oxygen cores, in order to
investigate the ages of millisecond pulsar systems based on the cooling
properties of the compact companions. Contrary to the behaviour of more massive
white dwarfs, the evolutionary speed of low-mass white-dwarf models is
substantially slowed down by ongoing hydrogen burning. By comparing the cooling
ages of these models with the spin-down ages of the pulsars for those systems
for which reasonable information about the compact companions is available, we
found good correspondence between both ages. Based on these models any
revisions concerning the temporal evolution of millisecond pulsars do not
appear to be necessary.
