My question is this. My ex wife and I have agreed to visitations every other weekend with our two children. We also agreed to alternate major holidays. The question is, Christmas this year falls on a weekend, It happens to be my weekend and she wants to take part of my weekend for Christmas eve and give the kids Christmas day. Now our agreement is that the weekend starts at 5pm that friday and goes to 5-8pm Sunday. Do I have to give up part of my week to satisfy her thinking Christmas eve is a major holiday of its own? :)

Holiday visitation can go many different ways.

The CP gets the child for the entire holiday (Christmas Eve and Christmas Day) in odd years, the NCP gets the child in even years (or vice versa with the CP geting even and the NCP getting odd).

The CP gets the child for the entire Christmas Break in odd years, the NCP in even (or again, vice versa).

Christmas Eve and Christmas Day are considered 2 separate holidays and they are rotated in even an odd years.

Regardless of which way is used, holiday visitation supercedes normal weekend visitation usually. So, for example, if it's your regularly scheduled weekend, but you have decided that the CP gets the entire Holiday in odd years and the NCP gets even years, then the CP would have the child for Christmas Eve and Christmas Day even though it's your "normal" weekend according to the schedule.

You didn't put the name of your state, but some states' parenting plans do separate Christmas Eve and Christmas Day as 2 separate holidays.

So... what exactly was your agreement for Christmas? Splitting Christmas Eve and Christmas Day, one parent getting both days in even/odd years, one parent getting the entire break in even/odd years...??

This is the sort of thing that parents should resolve themselves. You can go to court if you cannot agree, but I think you both should be able to work this out for the kids.