Only Have One Day at Disneyland? Yes, It Is Possible to Do Both Parks

You have to wait in line again every time to go from one park to the other, so try to get in as much in one park as you can before bouncing to the next. If your favorite rides are closed, one park is way more crowded than the other, or you want to get Fastpasses before they run out, those are the times you want to relocate.