Oh gosh, I really don't know. I don't time myself when I'm drawing, and I almost invariably work a little bit at a time over the course of a few days. I also don't have any sense of time passing when I'm drawing or writing.
Looking back at my critique thread, I posted the first 'finished' version on April 8 and opened Mythicarium to sell them on April 30, so a few hours at a time on and off over the course of 22 days. That's the best answer I've got.