The set xdtics commands converts the x-axis tic marks to days of the week
where 0=Sun and 6=Sat. Overflows are converted modulo 7 to dates. set
noxdtics returns the labels to their default values. Similar commands do
the same things for the other axes.
Syntax:
set xdtics
set noxdtics
show xdtics
The same syntax applies to ydtics, zdtics, x2dtics and y2dtics.
See also the set format command.