As the other comments indicate, this is an egregiously bad fake.
“Perpetual” is in reference to an automatic (i.e. a type of mechanical) movement; quartz is a battery-powered movement. Can’t be both things at once (unless it’s got Grand Seiko’s Spring Drive).
“Datejust” requires a date wheel/window, which is not present here.
Rolexes are Swiss-made watches, which have a “Swiss Made” marking at 6 o’clock. This example is lacking this marking.
As the other comments indicate, this is an egregiously bad fake.
Your grandfather was playing a joke on you.