@mrsm43s - It's really obvious to anyone who gives it any thought, that examiners work across all days, and many locations. It's not logical to assume that they only work on Saturdays, or will only be examining students from one particular dance school on any given day.
It's only logical if you have it explained to you first.
If you're new to the whole thing, it's reasonable to make certain assumptions. E.g. the dance teacher only runs classes outside school time so afternoons and weekends. I think it would be perfectly reasonable to assume the same for exams.
My daughter has been doing ballet for 14 years. I don't remember being shocked or surprised at the fact I had to take her out of school for the first exam (I was surprised at being asked to pay for costumes for the first show, but that's a different story). I can only presume (it's a long time ago) that is because we were given the information by the teacher, who is very organised.
Every exam, she sends a letter home (email now) saying your child is ready for the exam, it's not compulsory, if they don't do it, they will still move on to the next grade, details of when the exam will be roughly, with more detailed information as soon as possible. For younger kids, dates and times for the extra classes they were required to do for the exam is included and, I presume, for the first exam, it also stated that the exam could be during school time. She also lists what is required (shoes, colour of leotard, tights vs socks, pins, clips etc) and states that she will have helpers on the day to do hair so parents don't need to know how to do buns.
It's ridiculous to expect parents to know all that. Any experienced teacher should know that not all parents know this and should make it their business to give them the information so they can make an informed decision on whether to do the exam.