The movement of the hogs at my grandparents place seems to be dictated mostly by hunting pressure and heat. If no one has been down there hunting em for say 4 or so months, then well see them at crazy hours like 9, 10 AM rooting 50 yards or so from the house. Once somebody starts shooting guns at em from the deck (my cousins,not me) the hogs will go back to showing up at 9PM,10,12PM, 4/5 AM in more remote locations away from where they last got shot at. The late movement seems especially true in the hot summer months.
I'm not hunting em over feeders right now but when I was, they were always more likely to come in just after legal shooting hours. The sound of hogs rushing in is always a trip. I now do extra long sits over a caliche road (white rock reflects a lot of the moonlight) at or place, in a full moon w/o cloud cover I have enough light to shoot them (if I'm lucky enough to see em) w/o any artifical light.
Have you tried practicing with your bag in the darker hours of the evening??
Good luck.