I work ~8 hours a day, from Monday to Friday. If needed my working hours are adjustable per client needs. I understand and respect clients needs for deadline and in situation of emergency, I can also work for the weekend if agreed.
While general project discussion can go through skype, I would like detailed project instructions to be given in a different way: e-mail or PDF where everything is clearly defined and no room for misunderstandings.
Of course using project management system like Active Collab would be ideal.