I have regular 'work' hours during the week- sometimes until noon on Saturday if I have a deadline- or project I need to get done- outside of my regular 'work hours' I have my time to work on what ever I want. if you are going to treat your 'hobby' as a business you need to write up a 'business plan' including budget, operating hours, policies, prices...once you have it figured out in black & white it is easier to manage your time (and money)