A Child Custody Journal is a term for keeping notes,
notebook or a journal that helps provide a fairly systematic and steady journal
of both good and bad events when your children are with you or the other parent.  It is showing both the positives and the
negatives; showing the activities that are occur; what is occurring during your
parenting time and other parents time. 
It helps significantly in terms of being able to show to a judge, your
attorney, mediator or a Guardian ad Litem the time that you are spending with
your child; what you are doing during that time; if there are any issues at
each pick up or drop off; if there are any issues when the child comes back to
your home; anything from being hungry right away or not having appropriate
clothing or not having their homework done but it is important to have both the
positives and the negatives for both parents. Although, tedious it can end up
being a very helpful tool in a child custody or a parenting case.