Shared Custody: Organizing Your Schedule with Even and Odd Weeks

The even/odd week system is the simplest and fairest method for organizing shared custody. Learn how it works and how to apply it in your daily life.

What is Shared Custody?

Shared custody (also called joint physical custody or 50/50 custody) is an arrangement where a child lives alternately with each parent. Most commonly, the schedule is one week on, one week off.

To organize this alternation clearly and predictably, the even and odd week system has become the standard. For example:

• Even weeks (2, 4, 6...): child is with Dad
• Odd weeks (1, 3, 5...): child is with Mom

Why Use Week Numbers?

This system offers several advantages:

• Clarity: no ambiguity possible, each week has a unique number
• Fairness: over a year, each parent has exactly the same number of weeks
• Simplicity: easy to communicate to schools, babysitters, grandparents
• Predictability: you can plan months ahead without complex calculations

How Does the Custody Changeover Work?

According to the ISO 8601 standard used internationally, the week starts on Monday. The custody changeover typically happens:

• On Monday morning at school (Parent A drops off, Parent B picks up in the evening)
• Or on Friday evening / Sunday evening depending on your agreement

Practical Example

If we're in week 4 (even) and Dad has even weeks:

• The child is with Dad from Monday to Sunday of week 4
• On Monday of week 5 (odd), the child goes to Mom's

Frequently Asked Questions

What happens at the New Year?

Week 1 of January can be even or odd depending on the year. That's why it's important to use a reliable tool to check the week number, especially around the holiday season.

How do you handle school vacations?

Two approaches are possible:

• Continue the rhythm: keep the even/odd system during vacations
• Split the vacations: vacations are divided in half, regardless of week number

The most important thing is to clearly define the rules in your custody agreement.

What about holidays?

Holidays typically follow the normal weekly schedule. Some parents choose to alternate specific holidays (Christmas, birthdays) independently of the regular schedule.

Practical Tips for Co-Parents

• Use a shared calendar (Google Calendar, Apple Calendar) with week numbers displayed
• Inform the school of the schedule so they know who to contact each week
• Plan ahead for events: birthdays, school trips, medical appointments
• Communicate: a quick message about any changes avoids misunderstandings

Check Any Date

Use our free tool to instantly find out if a date falls on an even or odd week:

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