#ifdef SI
#define UNIT cm
#define POS -2,-2
#else
#define UNIT inch
#define POS -0.75,-0.75
#endif
.TP
.B \-U
Draw Unix System time stamp on plot.  User may specify where the lower left corner
of the stamp should fall on the page relative to lower left corner of plot in UNIT [Default is (POS)].  Optionally,
append a label, or \fBc\fP (which will plot the command string.)
