The difference is scheduling versus just hoping you'll get a driver. When you schedule a day prior, drivers have an opportunity to pickup the run in advance. I've frequently done pickups at 4-6 a.m. and every time the driver was there on time or early.Cached
Does Uber confirm a scheduled ride?
Your trip request is only confirmed once you have received your journey details. However, your driver remains free to cancel your trip request. In this case, the trip request will be offered to another nearby driver. Please note that Uber cannot guarantee that a driver will accept your trip request.