Could be a few days or less; could be a year or more. Acrylic paint dries fast, almost immediately, while oil paint is very slow to dry. Water color dries fairly quickly but if you are using a wash you want it wet. I use oils so it's usually at least a month, and then longer to dry enough to frame. If you start out with a sketch that you transfer to your surface that's hours or days before you start painting. There is no set time; it takes as long as it takes.

Do it all in one sitting, usually 2-3 hours and I stop until the next day or next week.

Check out Louise Fletcher, Nicholas Wilton and Ian Roberts on YT for different ways of considering the work at various stages.

I make quilts. Some take days and some take years. Most are somewhere in between.

... over the past 60 years has been commercial illustration, deadlines have never afforded me the luxury of taking my time on a piece. That mindset has become so ingrained that even commissioned paintings are subject to the same determination to get the job done, but done well.

Who is yall and why does yall want a painting?