The repeated time-stamped "Mon Apr 23 xx:xx:xx PDT 1990" lines displayed with
the "apropos dt" command are caused by the /usr/lib/whatis database file. The
"apropos dt" displays any line matched with the "dt" string (not case
sensitive) from the /usr/lib/whatis file. The workaround to this minor
annoyance is to remove these time stamp lines from the /usr/lib/whatis file.