Am I unreasonable not to agree to his new child access rota

The ex is only threatening court because OP isn't agreeing with his proposed arrangements. Which is her right of course but unless she's got a very good reason she won't win in court. It's about being pragmatic.

Okay, but I got the impression the ex has it in his head that he's doing more than he really is.
I do think you can go back if the first agreement was rushed or it hasn't worked out when tried in real life. But it isn't the OP who is set on court - she can't control it if her ex is adamant. Mediation would be better and she has proposed that.
I can see why she's pissed off though - everything is set up to accommodate him and no consideration has been given to her life despite the fact she's doing 2/3 of the childcare.

I don’t understand the schedule as well as some of the responses here do but I wonder if there’s a deal to be done around him providing you with additional childcare payments, if this is interfering with your work.

I must say that trying to force him to look after his children when he doesn’t want/isn’t able to, doesn’t sit quite right with me because they deserve stability and shouldn’t feel as if they’re being passed from pillar to post. I appreciate they’re his children but that’s not going to stop an 11 year old feeling pretty wretched if they know they’re not wanted.

If he is genuinely working those long shift patterns and you end up securing your 50/50, it will be necessary for him to get childcare anyway, so the more “settled” scenario for the children is to have a solid home with you and him provide you with the means to increase childcare provision your end.

You’ve not said anything about how the children feel about all of this, or the level of care they receive whilst they’re with their father and presumably, his new partner.

The agreement isn't that all holidays are split, it's that they are split 50/50 where possible in line with his work. That's what's in the order and what he is proposing, but OP doesn't like it. It's too late to not like it though as the proceedings are over. You can't relitigate proceedings just because you don't like what was agreed.

So what happens when you go to work op?
The problem here is that the female is expected to put her estranged male first.
Why would his work be prioritised over hers?
Op you need to think of your future and put that first.
why can’t he care for his children for 3 weeks at a time?
Dies he work off shore like a previous poster asked?
What would happen if your job took you away for 3 weeks at a time.
Why is he not using his AL to look after his children?
YANBU.
Patents have to think before they accept jobs like his.
What maintenance is he paying?
Do the children benefit greatly from his very important job financially?
Your pension etc will be impacted by you having to do must if the childcare so think about that.
Once divorced you do not have to prioritise your ex’s work over yours.

OP I think this really does depend on whether you can reasonably manage the children during this time without it affecting your own work or childcare costs. I agree that you shouldn't have to constantly adjust because of the work patterns of a man you're not even in a relationship with, but equally, he might not be able to change jobs.

I think I'd focus on the positive point of him not actually asking for more time, just a different split - you still get your dc with you for the majority. Some people would see his total absence for weeks at a time as a bonus!

Since all holidays are supposed to be split, I'd be pissed off if he wasn't doing that due to his work schedule - how can he do 50/50 holidays if he can't guarantee getting half terms off, which are a week at a time? I would also make sure he's paying full child support and so you might need mediation or court for the details here if you can't work it out.

I think you're mostly annoyed that it's you having to adjust because of his work, that you never agreed to and that he dips in and out of parenting, which mums usually just don't do and it's really galling.

But overall, you don't lose anything with the change, so long as it doesn't affect your work/childcare. I would disabuse him of his half arsed idea that he's doing 50/50 though because he isn't!

So currently it is:

(Y) 2 weeks (him working), (H) 4 (Y) 3 (H) 4 (Y) 3 - is that right?

He wants it to be:

(Y) 3 weeks (him working), (H) 4 (Y) 3, (H) 4 (Y) 3, (H) 4 (Y) 3

Unless you have a work reason that this won’t work I think this sounds reasonable. It’s not ideal he won’t see them for 3 weeks but would be the same if you were still together and presumably had a similar job when you were together.

I can’t work out what your proposal is.

Someone has already explained this.
2 weeks, OP has them full time
Next 2 weeks, she shares with ex 4 nights him, 3 nights her, 4 nights him.
He wants to change to 3.5 weeks her
3 weeks of 4-3-4-3-4

It's really annoying from OP's point of view no doubt and she doesn't want to agree without a fight. But unless she has a very compelling reason why she can't accommodate it, court would likely agree. She also doesn't like the holiday arrangements that were agreed within the previous proceedings and wants to change them. Court will probably not agree to that, since they already decided.

So essentially he works a 2 week on/off pattern now, is changing to a 3 week on/off pattern. Currently he has them 50% of his 'available' time plus a bit extra in school holidays. The new arrangement he is asking for 50% of his 'available'' plus school holidays in his available time. It's not unreasonable, although it leaves you with longer stretches of solo parenting. It's not true 50/50 obviously, more like 75/25 but it's following the same pattern and percentages you've agreed to previously.

I cannot understand your post.

what is the current pattern, and what does he want it changed to?

example
Typical month
Days 1-4 you
5 -10 him
11- 21 you
22 - 26 him
27 - 31 you

I think the problem people are having understanding (me included) isn't because you're 'ranting' it's because you type everything as one long sentence with no commas or full stops, so we're having to try and put the punctuation in to make the text make sense. This last paragraph you wrote for example....

My original post was me ranting hence so many mistakes in it I feel that I'm just expected to say yes you do you I'll bend over backwards with whatever you say I won't question anything etc I'll miss out on 2 weeks with our toddler and eldest especially during the long school holiday because there's no flexibility he can't go so I will do 1 week on 1 week off etc for the duration of it because he doesn't take time off work / use paid holidays.

Thats one hell of a sentence without a breath. Try to break it up a little bit. If people can read it without struggling to see where one thought ends and the next starts, you'll likely get some better responses. Apologies if that sounds really critical, it's not meant to be, just trying to get you to see why people are having difficulty.

Three weeks on three off it a typical oil rig pattern isn’t it, and if you that includes annual leave, they don’t get it on top. It’s really unclear from your post what you want him to do instead of what he’s proposing.

Can you accommodate 3 weeks on 3 off?
Going back to court to quibble over holiday arrangements is not what court is for. You had the chance to drill down on this when you were in court before. They will not want to adjudicate on this again, especially if it's just because you don't like the agreement that was made last time.

I'm not making that argument myself, I'm anticipating what the court will say. If OP can accommodate 2 solid weeks on, she can probably accommodate 3 weeks. If she genuinely can't, maybe they do need to go to court, but it's a huge amount of stress and hassle probably for the outcome OP doesn't want.

Do you work OP? How does it fit in with your working hours?

What does your 11 year old want? By secondary school they usually like the stability of one home, not messing about with off days in a school week.

Many people cannot just change jobs these days! There aren’t the jobs. He’s probably stuck with his job arrangements. Many people are! I’d start looking at it from your DCs point of view. Not slicing a cake in terms of fairness to parents. What will work for dc? How much does it matter to them if the arrangements are over 3 weeks instead of 2? How will it impact them in terms of school and childcare? If he has tk work this pattern, then sticking to the 2 week pattern seems unsuitable and not workable. He’s nowhere near 50:50 with any of the two options.

That’s an interesting point about paid holidays. So you’re saying that he only has the children in his “off” weeks and doesn’t use annual leave to spend time with the children on top of that?

Frankly his job doesn’t sound compatible with proper shared parenting and I agree he’s asking you to accommodate his work schedule in a way that might be reasonable if you were together and a team but is very unfair on you now you’re not.

Unfortunately I think you were right that the court will probably agree that a man’s work needs trump all.

It depends if the op works, but the argument you make there is he can’t fuck off for 3 weeks because He hAS a JoB, when it impacts her ability to work, you have to share the convenience and inconvenience.

And of course sharing the holidays means sharing the term holidays, who in their right mind thinks it only means summer holidays?

I think you'd be really silly to make him take you back to court over this and you won't win.
I think he is correct in asking for 12 days over 3 weeks instead of 8 days over 2 weeks and if it's because of his work schedule he will probably get it.
I also think you're being deliberately obtuse interpreting half the holidays to mean half the summer holiday only. Orders pretty much always divide the school holidays this way and they include all holidays including half term.
Don't make this the hill you will die on, you'll end up being dragged through court with all that stress for nothing.

You are correct @Princess90x this is no where near a 50-50

on 2wk on 2wk off rota; he has them 8 days, you have them 20 days

3wk on 3wk off rota; he will have them 12 days and you will have them 30 days

With the current set up of 2wks on + 2wks off he has the children for 8 days.
4 Him+ 3 You+ 4(H) + 3(Y) which are his 2 weeks "on" (ie 14 days 4+3+4+3)

then all you for his 14 days off = 20 (14+6) days for you

On the 3 weeks rotation it will be
4(H)+3(Y)+ 4(H) +3(Y)+ 4(H)+ 3(Y) = 21 days which are his 3 weeks "on" (ie 21 days 4+3+4+3+4+3) then all you for 21 days and nights (his 21 days off)

Therefore over a 3 weeks on + 3 weeks off period (42 days) he has the children for 12 days (his 3 weeks on) and you have them 30 days

Are you also a working parent, OP? Or just father?

Op, if you want to make it easier for us, use some punctuation!!

So right now there are 13 four week blocks a year and he has 8 days of parenting in each of those blocks. That gives him 104 days of parenting a year.

he wants to change it to 8.67 6 week blocks. If it is 12 days of parenting per block, he will still have 104 days of parenting a year. If it is 8 days, it will only be 69.3. Him asking for 12 days if the block schedule changes makes sense.

The bigger question is the impact on your ability to work. It is not your responsibility to adapt to his needs. Many parents in intact families would get a schedule change like this and instantly start looking for a new job because it doesn’t work for their spouse.