In a perfect week I would play 1/2 hour before I am too tired to function.  Right now I play about 20-30 minutes before bed, once everything else is taken care of.  Ideally I would like to move that to earlier but right now that is the best time I have.  Maybe after the summer (I’m also training for a bicycling event) I will be able to reserve some time in the morning before work or at lunch time to practice.  I usually play in my room once everyone else has gone to bed.  I used to play in the garage (which was ok) so as not to disturb anyone.  I play at least 5 x a week, ideally 7 x a week.