Typically when a child is involved in a divorce, they will address a formal custody agreement. This is soley based as a guidline for parents who cannot agree. If your divorce is uncontested, you have a history of being able to work together and get along, they it is highly likely the judge can allow you to have an open custody agreement, allowing you two to come to visitation agreements on your own.
The childs age does play a role - in that if 12 or older, the childs wishes concering whom they would like to live primarily with would be taken into consideration, unless 50/50 shared is awarded. - provided its in the childs best interest.
If the two of you agree for the child to go on a trip during the divorce process, that is completely fine.
The formal agreement will go into place when it has been filed. The filing of the order differs in time, depends on how you are doing the divorce, and if its contested or not.
The laws of your state could be slightly different, to get a standing answer, consult a family law attorney. Most will do a free consultation - which is perfect for asking questions like this.
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