That schools/some schools are taking away any rights of parents to parent there children. I was told i had to cancel and rearrange an appointment for my son for dentist work, (baring in mind he is in pain) because a school trip happens to fall on the same day..the appointment has been booked for several weeks and had the letter about trip afterwards. So its not as if i booked the appointment knowing there was a trip on that day. He has also been to the same trip with previous school so he isnt missing out that much and has told me he wants his tooth sorted out.