Maximum of three hours. I usually spend a lot of time preparing, reading, and planning. After completely understanding what needs to be done, I start writing code. Before starting my day, I think about what needs to be done today. Then after exercising, refreshing, eating breakfast, I start preparing for the project. At 12:00 pm I start writing code and after lunch, I take a nap. A power nap makes me refreshed but I don't write code afterward. I just read and write till dinner.