The Ashtanga method is an embodied tradition,
intended to be a done daily and the students
are encouraged to make a commitment to
practice. Its transmission is one-to-one and mostly experiential. 

Saturdays, new and full moon days are days of rest
and women are recommended to not practice during
the first three days of their menstruation and rest instead.

It may be very difficult at first to commit to a daily
practice, and it often takes time to establish this.

But you are not in a hurry, are you?

To establish a regulary  Ashtanga practice it is recommended
to start with three times a week and to allow the practice to
slowly integrate itself into your weekly routine.  
It is recommended to do a little bit regulary rather
than a lot once in a while. Continuous repetition is the key!