I am so confused by this thread.
Why is he working 2 jobs? Is it because he wants to… or needs to? Most “high earner” jobs, of the type that is being assumed here ( lawyer, banker, professional services, £250k+) don’t allow for additional “project work”. Possible he doesn’t earn as much as you think and is struggling to keep up as the sole earner?
He is looking after the kids for an hour in the morning and two hours in the evening. Is that with you OP? Alongside you? That seems a reasonable amount of weekday involvement for a working parent of school aged kids.
When you say he works at the weekends … literally every day of every weekend in the year? Is that on his first job, or on his “project work” job?What has he said when you have asked him to free up some time? eg if you asked for a day per fortnight for family trips? Does he say he can’t because of a deadline, or because he won’t earn enough, or that he just doesn’t want to? Or if he frees up time at the weekend does that mean he won’t be able to help out so much with the kids in the week?
You say he works during the holidays, but then I think you made reference to the 6 week school holidays. Do you mean he doesn’t take any time off at all? Or do you mean he takes some days off with the family (e.g. a weeks leave), but other days of the school holidays he has to work (which would be normal)? Or is her perhaps trying to compromise by working flexibly, working mornings during the holidays and taking afternoons off, rather than taking full days off?
I suppose what I am getting at OP is what are your expectations of what his work/family/rest pattern should look like? Because it seems to me that your expectations might (and I do mean might) be a bit off. I say this as a high earning sole wage earner with a SAH DH and school aged kids.