But, consilis, was that primary? We have huge pressure on us at high schools to get pupils through exams. There are 38 weeks in the school year and, in Scotland, all courses are one year courses (some schools are stretching them out over two, but that's a different thread). So, I only have time to teach, for example, a WH Auden poem, which I did this week, once.
Now, one pupil is away on a vital (for that read, they fancied one) family holiday. She will miss the poem and all associated work. She will want to catch up. I am not expected to help her but, of course, I will as it is not her fault her parents prize a week in the sun in Tenerife over her education. I will then give up MY time. When she fails (if, but she is very borderline already) then the holiday in the middle of term will have been forgotten. Her failure, however, will be laid at my door, and not just by parents: it appears on school and departmental statistics. It may form part of an inspector's view of a school....I could go on.
As for forces children, I still think the way you show most concern for your children is in telling them they have to attend school. My father worked away in dangerous places (oil, not forces) for much of my childhood and we just saw him as and when. However, we all have, as a result, a tremendous work ethic, because he did (and my Mum, home alone with 4 daughters, often overseas).