How do Muggleborns explain their term-time absence to others?

How do Muggleborns explain their absence at home during term time to primary school friends, neighbours, extended family and family friends? Their parents and siblings can know about magic and Hogwarts, but others couldn't. I know some could claim they're away at a normal boarding school, but that wouldn't work if the family couldn't afford one o have been too obvious in their dislike of such establishments? What would be the cover story then?