I finally tired of wondering how many hours of sun my two side lawns get, so I observed them in late August. One side lawn faces the southeast approximately, and the other side lawn faces the northwest approx.

Because of the positions of the sun and my roof and my two neighbors' roofs, I can say each blade of grass in the side lawns gets roughly 3 hours of sunlight--that's not a lot obviously, but it's enough to support Meyer zoysia, since that's what's mostly growing there. But 3 hours is a rough average. I'd estimate the amount of sun enjoyed by each blade in the side lawns varies from about 2.5 to 4 hours depending upon the blade's location in the side lawns.

In late August, both my side lawns are pretty much completely shaded until about 11:30 AM to noon, at which time half of the northwest side lawn (and half of the southeast side lawn) is bathed in sunlight while the other half of each side lawn is still in shade. Over the next 3 hours until about 2:30 PM to 3 PM, the percentage of each side lawn that becomes lit up in sun grows until each side lawn is 100 percent in sun--no more shade anywhere in the side lawns. But the shade doesn't stay away for long at all. It slowly grows in size until the first lit half of each side lawn becomes shaded.

By 5:30 PM, each side lawn is almost completely shaded again, except for a quarter of the northwestern side lawn that is closest to the backyard and my house. The other 3 quarters of the full northwestern side lawn are shaded. The lucky lit quarter enjoys sun until about 6:30 / 6:45 PM in late August when I made these observations. The lucky lit quarter actually has some bluegrass growing there instead of zoysia. Maybe the zoysia got taken out years ago by being submerged during heavy spring rains--not sure. But bluegrass doesn't do that well either in submerged conditions, so I don't 100-percent know why the bluegrass beat the zoysia there.

So how much sun does your side lawn get?