Our holidays are boring and predictable and do not normally intrude into tutorial planning. We have one holiday in late July or August during the school vacation and another in February (normally the week before half term and the week of half term). This second holiday is not usually at a time when anything crucial is happening at GCSE or A level. If necessary we will prepare work for students when we are away.
You will also go on holiday. We understand this and plan around it. Many parents stop tutorial sessions during school holidays but others want to continue throughout. We will accommodate either requirement.
Similarly illnesses happen to both us and to students. We just work around this. Most important really is as much information as early as possible from both parties. We are very adaptable and do not usually charge cancellation fees.