Ugh, that is terribly manipulative behaviour, to tell the child something that hasn't been previously arranged between the adults, in an attempt to force the other adult to agree. My ex still does that, and it sucks. Although usually it's done to make you look like the mean parent, and in this case it seems to have backfired. Tell the child that you are still working out the exact day of departure with his dad, but it's dad's turn for Christmas so everybody has to deal with that and make their plans accordingly. He'll only miss a boring Christmas at Mom's because she's just going to spend the week cleaning because the real excitement is going to be New Years' there this year. Open stockings at midnight while drinking sparkling juice from fancy glasses!
Order states Christmas vacation shall be shared equally
Last day of school is Dec 22. First day back is Jan 8.
So Christmas holidays are 23Dec to January 7. 16 days so 8 days each.
Dad is now saying he should have Dec 22 noon ( when school gets out) to Dec 31. Mom is saying it’s Dec 23 to Dec 30 as per past practice and the agreement has been interpreted I. The past. 8 days each.
Dad insisted on the order that child is to be brought to the airport so that what it states. Now he wants to pick up from school.
So these previous 'past practice' of the holidays being Dec 23 to 30 have been regardless of the school schedule? How much has that deviated from the order in the past? Deviating is on a case by case basis unless you mutually determined you like the deviation better and want to keep it going forward so you both agree to a Motion to Change and enshrine the deviation in a new order.
You haven't done that, so...
Shared equally makes me think the first week belongs to dad this year, and the second week belongs to mom. Not dad's week happens somewhere in the middle. Is there some practical child-focused reason that pickup at school on the 22nd doesn't work? There are 17 overnights between the 22nd (last day of school) and the 8th (first day back). It's very hard to share that perfectly equally unless you propose to wake the child for a middle of the night exchange.
Dad proposing Dec 22 to 31 gives him 9 overnights, leaving 8 for mom. That's 8 full days and two half days to dad, and seven full days and one half day to mom. I don't think it's unreasonable at all for a parent with so little access to have the extra bits of time.
You could always counter with being okay with pickup at school on the 22 (that saves you having to drive to the airport or even see dad - win!) if the other exchange happens on the 30th instead of the 31st. That gives dad 8 overnights and 9 for mom, 7 full days and two half days to dad, 8 full days and one half day to mom. I don't see that it makes a huge difference though unless you have plans for a long drive somewhere that exchange weekend for your holiday destination that you would prefer to be able to do earlier?