Thank you for the reply. The situation is that in the divorce agreement there is no suching saying about 7 weeks in the summer with the dad b/c local distance. In that agreement, it says the child stay over with the dad every other weekend and the dad is entitled to have one month of vacation with the child each year. The child can't move 50 mile away from the current location.
The mother's relocation is due to that the job in DC is the only offer she has.
Now b/c of the mother's relocation we are negotiating the new agreement on visitation schedule. The new schedule is, each month the mom bring the child to his dad in NY once. The dad can visit the child in DC anytime given reasonable advance notice. The dad is entitled to have 7 weeks of his son in NY during summer. So the mother feels she should also have right to visit the child in NY during the 7 weeks when the dad having the child. But the father questions whether she should be entitled to this visitation b/c she has the child most of time during the school year.