Shared Parenting Time (formerly shared custody) is when overnight parenting time with the children is substantially split. Once a parent has more than 40% (146) overnights per year, child support is typically reduced. There are ways to deviate from that guideline but you should consult with an attorney about that possibility. This custody calculator may help calculate the total average overnights for weekly parenting time when parents have different overnight schedules from week to week.