I too hunted the A zone a lot for many years in the Livermore hills and those hill around Mt Diablo. It got hot early and stayed that way unless we were lucky enough to get the evening fog to roll in during the evening hunts.
We as a group pretty much hunted all day but took a nice long lunch break, played some Pedro, and took a nice nap.
When by myself off walking, i'd use hours to get where and how i wanted to be just before the sun went down or came up. A lot of my bucks were taken just at dark as bucks left cover on their way for a drink that they just couldn't wait any longer. Those few minutes were so important as our country had a brush that a person just was not going into or find anything other than misery and those bucks knew where to go and stay to be safe. It was great when a plan came together on a particular better buck.
Hunt you best spot until the last second that you can and walk out in the dark!
To find deer during the heat of the day, we had several ranches that had long oak and laurel tree infested north slopes. the deer liked to bed up under the packed together laurel trees(that's the tree that grows Bay leaf) or where there were buck-eye trees mixed in with the oaks. The important thing was the darker the shade the better and not too far from water.
Those days were a good bit ago but the hunting there in that country and country like it, still applies!
Joey
"It's all about knowing what your firearms practical limitations are and combining that with your own personal limitations!"