Montana Parenting Time Calculator

Montana calculates parenting time by counting the total overnights each parent has with the child during a calendar year. Under ARM 37.62.124, a "day" means the majority of a 24-hour period (over 12 hours) when the child is with or under the control of a parent, with the calendar period beginning at midnight. When children are in third-party care such as school or daycare, the parent designated as primary contact is credited for that time.

In Montana, a parent must have more than 110 overnights per year (approximately 30% of the time) to qualify for the shared parenting child support adjustment under ARM 37.62.124. When both parents exceed this threshold, child support is calculated using the shared parenting formula in ARM 37.62.134, which reduces the transfer payment proportionally. Parents with 110 or fewer overnights receive no adjustment regardless of their exact parenting time.

The 2-2-3 schedule is a 50/50 shared parenting arrangement where children rotate between homes every few days. In Week 1, the child spends Monday-Tuesday with Parent A, Wednesday-Thursday with Parent B, and Friday-Sunday with Parent A. Week 2 reverses this pattern. This schedule provides approximately 182 overnights per parent annually—well above Montana's 110-day shared custody threshold—and works best when parents live near each other.

Parenting time directly impacts Montana child support calculations because overnights determine whether the shared parenting adjustment applies under ARM 37.62.124. When the non-custodial parent has 110 or fewer overnights, no adjustment is made. Above 110 overnights, the child support obligation decreases proportionally to account for duplicated housing, food, and care expenses. In equal 50/50 arrangements with similar incomes, little or no support may be owed.

Yes, Montana allows parenting plan modifications under MCA 40-4-219, but you must demonstrate a change in circumstances since the original order and prove the modification serves the child's best interest under MCA 40-4-212. Courts typically will not consider modifications filed within 6 months of the original plan, and a motion filed without good faith compliance with the existing plan may be deemed vexatious. You must file and serve a proposed amended parenting plan with your motion.

Montana courts recognize that infants (under 18 months) and toddlers (18 months to 3 years) need continuous contact with their primary caregiver while also developing attachment to both parents. Experts recommend shorter, more frequent visits for young children rather than extended overnights. Many Montana families use step-up parenting plans that gradually increase overnights as the child grows—starting with several short visits weekly and adding overnight stays as the toddler adjusts.

Montana parenting plans typically alternate major holidays between parents annually. Common provisions include alternating Thanksgiving break by odd/even years, splitting winter break at the midpoint (one parent gets Christmas, the other New Year's), and dividing summer vacation while maintaining the regular schedule. Mother's Day, Father's Day, and children's birthdays are usually spent with the relevant parent. Montana courts will approve any reasonable holiday schedule parents agree upon under MCA 40-4-234.

First right of refusal is a parenting plan provision requiring each parent to offer the other parent childcare before using a third-party babysitter or relative. For example, if the custodial parent needs childcare for a weekend trip, they must first ask the other parent if they want that time. Montana parents typically set a triggering threshold of 5-8 hours—shorter absences don't require notification. This provision maximizes parenting time for both parents and reduces third-party childcare costs.