As long as it takes for me to go wash my hands, eat dinner, watch some TV, play with the dogs, and muster the ambition to go back out to finish the job. Sometimes that's overnight.
Until I feel like it. Dribble or drip. If I was "wise" I'd do the tire rotation while draining, then call it good.
Lots of oil gets left behind in nooks and crannies; I'm not about to pull valvecovers to vacuum out the dregs. Same goes for the pan, which usually holds a bit that won't ever drain out on its own.
On my truck, I remove the drain plug, then remove the oil filter to drain. I get out from under the truck, lube, fill and install the new filter, by then the pain is empty enough, install the drain plug and fill w new oil.