I have two days off a week (that are child free) so I would say 2 or three hours each day, making between 4-6 hours plus if like last week I'm cramming for auditions, an extra hour most nights after work and a few hours on a Sunday, getting randomly interrupted by a 5 yr old girl & her pink ukelele who tries to distract me & feed me biscuits.
So roughly ten - twelve ish hours if needed.
4 to 6 hours if not.