He said a Friday evening until Sunday suits him fine to have them every week. I told him I'm not discussing it right now but I work mon-fri and would like some weekend time with them too so we will hopefully come to an agreement. What to do now...
He's still being selfish. The family courts typically want every other weekend with either parent, because that's the fun time. Weekdays is the grunt work, when you have to focus on meeting their physical needs alongside working yourself. Standard split is either a shared care arrangement (rarer, because it can unsettle kids, but not unknown) or every other weekend, with a mid-week overnight (usually Wednesday) each week if the parents live close enough together.
I don't know if you have mediation in Scotland? It's a useful way to thrash out arrangements with a neutral 3rd party, if you do. But in your position and with regard to some stability for the girls (I doubt they will want to live with his new situation that soon) I would think every other weekend and maybe a weekly overnight might be a good idea. Maybe talk with the girls and get an idea of what they would like, going forwards from now? As he's not reliable might be an idea to stress they're just ideas, and "Daddy's work might not make that possible" (boak). But it would give you an idea of what would work best, alongside what they would like to happen if they chose for themselves.
I haven't been posting because you're getting so much great support, but I have been thinking of you so much, and admiring your strength and honesty. I wish we could collectively get you past these horrible weeks and on to the gentler waters of the future, but as we can't, please know that you could not be less alone. A lot of women all over the British Isles are thinking of you and your daughters. xx