Teachers get ten sick days per year, plus three personal days, if needed.
As I pointed out, it is not always possible to schedule your personal days on days when there is no school. Teachers may use the sick days when they are ill, or to care for an ill person in their family.
Someone pointed out how many times school is not in session a full five days in a week. Many of these days are teacher work days, when staff has to be at school, or at a workshop location, all day. If they are not in attendance, they have to take leave. So just because your child is not at school for five days a week every week, don't assume the teachers are home, sleeping in.