Maybe I’m missing a trick, but my understanding is that state schools are open 38 weeks a year, 38 for staff so 5 INSET days. I work in education at the local authority, so this is what we do.
My DD’s school have just published the term dates for next year with 5 in school INSETS, and an additional academy chain wide INSET.
Surely if they want to do that they should only have 4 in school insets to compensate?
(I may be being over sensitive to this, but DD only had 3/5 days in nursery last week due to this 6th inset day plus closure for new kids trail day, we were told that they were having the extra day this year as they joined the academy half way through the year and dates were set!)