My preference is to feed fruit meals early in the day – usually before noon, because they are very water-rich and this means the dogs need more potty breaks. If we feed fruits too late in the day they can have us up all night for potty breaks so I typically feed fruit meals between 8 am and 10 am and my absolute latest is 4 pm for denser fruits like bananas and noon for watermelon or other melons.
For meat meals, I choose to feed them in the evenings because they tend to be more sleepy after their meat meal. Around 7 pm works well for us because they come in from playing all day, have their meal, and then by 8 or 9 they are all tucking themselves into their crates for the night.
In nature, dawn and dusk are when they would be primarily eating, especially for prey meals. The low light makes the hunt more likely to be a success. During the heat of the day they would be resting. On fruit days they might forage for several hours but they would still be resting in the warmest part of the day.