In the late 1950s and early 1960s, I attended a boarding school in the Midlands region of England, close to the Cheshire border.
It remains a boarding school to this day with a similar name, so I will not mention that name, despite the school having gone through a number of changes.
When I attended it was a progressive, privately-run, fee-paying school and for the first two years my dormitory was mixed, containing girls and boys age seven through to nine.
In their last two years, as seniors, girls and boys were segregated.
In my class, there were usually 24 pupils (not students as they would be called now), up to eight of whom were day pupils and the others, like me, were boarders housed in a single dormitory.
Boarders arrived at least two days before the school term began, usually on a Friday or Saturday, since all terms began on a Monday.