Misunderestimated

I realized that I underestimated the number of days it would take it finish my current painting. I thought that I would be able to work on it continuously for several hours. However, I have been only working on it for 20-40 minutes at a time. This is due to the fact that there are only 3 distinct areas on the painting, so I can't just jump to another area while I am waiting for one area to dry.