[mythtvnz] epg and mythfilldatabase updating

[Roger Searle]

I have managed to get the EPG to populate mythtv.  Eventually.  And I'm 
somewhat unclear as to whether I have it configured to automatically 
update mythfilldatabase.  These are the steps I took to get this far:

I have tv_grab_nz-py in my /.home/roger/.mythtv folder, and copied to 
/usr/local/bin, it is executable.

I've run tv_grab_nz-py --configure and have a 
/home/roger/.xmltv/tv_grab_nz-py.conf file.

I downloaded the freeview.xml file from nzepg.org then ran 
"mythfilldatabase --file 1 freeview.xml --update".  I continued to have 
"unknown" in the mythtv program listings until I used mythweb to add 
xmltvid data for each channel.

Now I have EPG populated, I turn to it's automated updating and see the 
default backend settings for mythfilldatabase as follows:
Automatically run mythfilldatabase (tick)
Mythfilldatabase program: /usr/bin/mythfilldatabase
Run mythfilldatabase at time suggested by the grabber (tick)
Arguments blank
Run frequency (days) 1

I suspect I need some arguments passed in order to involve tv_grab_nz-py 
but don't see if/how/where I may need to do this.  Could someone offer 
guidance on what I may need to do?

Cheers,
Roger