Comment by yason

I don't know but to me this all sounds like the antithesis of what makes programming fun. You don't have productivity goals for hobby coding where you'd have to make the most of your half an hour -- that sounds too much like paid work to be fun. If you have a half an hour, you tinker for a half an hour and enjoy it. Then you continue when you have another half an hour again. (Or push into night because you can't make yourself stop.)