Also, think I've been a bit hasty and have concentrated on the fact that OP wanted DH to take time off work so she could have time to self, when maybe, like others, I shouldn've focused on the fact that he takes time off for himself.
I'm not really heartless, it's just I wouldn't expect my DP to take time off so I could have time to myself bacause he gets bugger all time off anyway, and I would think he was wasting family time if I expected him to use his time for me, IYSWIM.
But given that he does this for himself. If I were in OP's shoes I think I'd try and strike a deal. Eg he uses minimum time off work for his hobbies, and whatever time he does use OP gets equal time back in lieu either by him booking time off work or by letting her have the equal amount of time spread over the weekend.
It sounds a pretty disjointed unhappy set up tbh but it might just make him realise that this is all too one-side. It might even make him stop booking time off work for his hobbies. ANd goodness knows when the DCs will get to spend time with both parents together, though!
Unless, of course it's only a couple of hours each month in which case what's all the fuss about?