it depend how well I want, from minutes until weeks. Usually for sketch I finished it in 1 - 2 hours. But painting 8 hours - 3 months. It also depend the level that I aim for, amateur / professional.

For some it might depend mostly on motivation or mood, and for my ETC... Let's just say it's solong that people thinks I forgot their request. Not good at drawing really much... Just draw for fun ^^

well I realized the more you draw the faster you get what you want. I guess your hand just get use to it :)

Pictures posted here is usually between 2-4 hours :) !

Light: It depends a lot for me. Since I'm a chick and all, first I have to get over my giggles. xD Once I'm over that, it entirely depends on the complexity of the picture. On average though, nowadays I take about 4-8 hours for a drawing

As scarlet pointed out just before i widely depends on your skill and how known you are to the style you draw it in. How complex the drawing is and how much thought you put into it.
On average i spend 3-4 hours on an uncoloured picture. and 8 hours to 3 days on well coloured/shaded/textured pictures

Depends on my mood and the pose/content for me. Comic pages might take an hour or two, but so might a pin-up if it's super detailed. Plus if I'm not in the mood to draw it takes longer.