Primary Custoday - Sick & vacation days

If a parent has primary custody, does the other parent have any responsibility to watch the children when they are sick or have vacation days from school? I am trying to figure out how I would coordinate all of this time off from work if I have to be responsible for all of the days.

Hello. If you have primary custody. It is your responsability to ensure that proper care is give to the minor children while in your custody. If the other parent is close by and that parent can and will agree to watch the children for a specific time, then the two parents agreeing on custody times will by default over ride and court order.
Me and my X do this annually. We break the wording of our decree when needed for the benefit of out children. If any attorney tells you that your are in contempt of a court order then you can tell the attorney and the judge to put both of your in jail. That is said in houmor. Actually any judge will agree that if two parents make an agreement to the bette of the said children, the court will recognize this as a positive action.
Moms and Dads spend their kids future college money to go into battle in a court of law all the time. The only time this should be considered if there can not be any agreement in custody arrangments outside of court. NOTE OF CAUTION. If you and your X are arrogent and hardheaded enough to do battle in court, you are essentially bound and will have to pay additional money in the future to have things changed. Look at it this way. If the minor is young, say 2yrs olf. There is 16 more years of a split family for this child to contend with. The funds to battle in court could be set aside for the childs college needs. Think about it.