The 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
unset xdtics
show xdtics
The same syntax applies to ydtics, zdtics, x2dtics, y2dtics and cbdtics.
See also the `set format` command.