I could not seem to find any documentation on the electronic program guide scraper configuration for the North America DTV XMLTV scraper. It needed to be documented.
tv_grab_na_dtv --configure. This should bring up the DTV EPG grabber configuration wizard.
htsuser that Tvheadend creates during the package install, then
cp ~/.xmltv/tv_grab_na_dtv.conf /home/hts/.xmltv/tv_grab_na_dtv.conf. Do be sure to
chown hts /home/hts/.xmltv/tv_grab_na_dtv.conf.
I increase the Grab interval when I first start Tvheadend to populate EPG data quicker. Usually, I leave the interval in the range of about 3 hours. One could have it even longer, as 1-2 weeks of EPG data come in.