I have 2 different prices for if the child is full day or half day (I have children who come in for my am preschool program) but the price doesn't change if a child comes 2 days or 5. Same price per day. The difference I use though is that if a child attends at least 4 days a week on a regular schedule, they are entitled to 6 free sick days per calendar year. If a child attends less than 4 days, they pay for the spot whether they attend or not.