Again another one going against the grain here. I’d be annoyed.
You were brave to post in AIBU because frankly you’ll always get a kicking. People who just made their 5 year walk from home on their own…
Most schools do something first few days/weeks which means parental involvement is needed (half days etc, later start), and too many men let the mental load and actual work fall on their wife/partner. They’ll attend if they can, but they won’t ensure they do.
I work full time so does my DH. I am the breadwinner and have a job which means it’s only absolutely emergencies I can’t attend. When my Father died I was back at work 36 hours later because there was something that could not be covered by someone else.
My DH works in IT and his job is more regular hours.
This is exactly the sort of thing he would do. Not take time off and possibly not even realise when first day is (I guarantee he has no clue when our kids go back), but say he would be there. Then suddenly something drops in the diary he can’t attend. It will not be an emergency which means his working are overriding annual leave (or the hour he took off am to attend). I on the other hand will have put this in the diary months ago so save for a dire emergency I will be there.
This year I have an important meeting happening. Has to happen that day. I’ve told the other attendees I have to drop one of my children off as they are disabled and have terrible anxiety and I will need to physically hand him over to his TA. We are starting at 10 am to accommodate this. I guarantee my husband has not even thought about it.
I presume OP is on mat leave, but it’s still the same issue. Mental load falling on women.