I am setting up farm shoots right and left

of stallions of different breeds that I want photos to paint from. After seeing Julie's late day shots I would love to get some at that time of day as well. I am sitting here trying to write back to a couple of the owners and not quite sure what to ask them about that time of day.
I am asking them first if the area where the horses are will be sunlit until dusk, we have so many tall trees here that many pastures are in shade earlier than dusk so that golden light never hits them. I'd hate to get there late and have nothing but shade.
Julie you said you got to the saddle club at 5 and the best light was from about 7:30 to 8. I guess that answers my question right there...I was wondering how long you have to work in that golden light, maybe a half hour or so? I will be taking a lot of running at liberty shots and want to be sure we have time for it all in the light. There will be multiple stallions in each case so I will need time to do each. I know the equine photography workshop in Ojai did their shoots about an hour and a half after sunrise and before sunset as well.
One of the places I am going have all black stallions(Friesians) but another has Andalusians and one stallion is black while the other is a cremello, a very light cream with blue eyes. I would like sun on the black guy definitely because I like to paint horses with sheen on them, it highlights the muscles and all so much nicer than flat shaded lighting. But full sun can blow highlights on the light coats. So I want to be sure I have time for both in the best lighting.
I want to go at a time when I will have plenty of time in the best light to shoot but without taking up hours of the owners day, everyone is always very nice and excited about having their horses photos taken but I don't want to overstay my welcome.
I will ask them if they know if their pastures are in sunlight until dark, and if they are then I'll ask to come around 6ish. If they aren't I'll go earlier. Having written this all down I answered several of my own questions, except how much working time there is in the golden light time of day, would you say an hour or so? Anything else I'm not thinking to ask them? I guess I need to do a couple practice ones on friends first!