Intermittent Child Care

Hi Parents, I am looking at Montessouri pre-schools but notice that many take a lot of time off and have "in service" days with no child care. The most Time off I have seen is between 2 to 3 months a year. I am interested in hearing from parents whose kid's school takes a lot of time off and they need to look for day care ranging from 2 weeks, 1 week, to one day each month. How do you arrange for day care? Both myself and my spouse work full time and don't have any relatives that can help out. 

Thanks so much!