With my 3200 lumen projector it is good at all times of day in my living room projecting on a wall that doesn't get direct sunlight shining onto it. It just can't make anything darker than the wall itself, so blacks are gray, which is not really an issue for me, although it might be if I were watching more movies during the day.

Previously, I had a portable project that only advertised 1000 lumens, and it was difficult to use during the day.

I would say that with a powerful enough projector it isn't really an issue unless you care a lot about black levels during the day.