A parent receives their judgment, reads “even weeks with the mother, odd weeks with the father,” and finds themselves counting the week numbers on a wall calendar while squinting. The problem is not the rule, but its concrete translation when the year has 53 weeks, when school holidays overlap two numbers, and when the exchange day falls on a public holiday.
The year 2026 has a particularity: it has 53 weeks instead of 52. Week 53 starts on Monday, December 28, 2026, and spills over into January 2027. For parents with shared custody, this shift can create confusion if one simply follows the even/odd logic without checking the ISO number of each week.
Week 53 in 2026: the trap that the judgment does not mention
Most judgments or parenting agreements simply use the formula “even weeks with one, odd weeks with the other.” This wording works in years with 52 weeks. With a week 53 (odd), the parent hosting the odd weeks ends up with week 53 followed by week 1 of 2027 (also odd), resulting in two consecutive weeks.
You can consult the even and odd week calendar for 2026 to visually identify this anomaly and anticipate the exchange.
If your judgment does not provide for this case, there are two practical options:
- Agree in writing (email or timestamped SMS) to a one-time swap to restore regular alternation starting January 2027
- Request a modification of the agreement from the family court judge if the other parent refuses any adjustments
- Use a shared annotated calendar (co-parenting app or simple printed PDF document) that highlights week 53 and its allocation
The reflex to have: check at the end of each calendar year if the following year has 52 or 53 weeks, and anticipate the discussion before December.
School holidays 2026 and even/odd alternation: two overlapping logics
School holidays follow their own calendar, divided by zones (A, B, C). During these periods, most judgments provide for a half-sharing that temporarily replaces the weekly alternation. The problem arises when the judgment does not specify whether the holidays “suspend” the even/odd counting or if they are added to it.
A ruling from the Court of Cassation on December 10, 2025 (n° 24-11.604) reminded that the judgment must concretely describe the day, time, and place of transition between even/odd weeks and holiday periods. Vague formulations referring to a “subsequent agreement between parents” are now more vulnerable to contestation.
Articulating holidays and numbered weeks without conflict
In practice, we distinguish two periods in the year: school time (governed by the even/odd alternation) and holiday time (governed by half-sharing, often even/odd years). The transition between the two creates a gray area.
Take the summer holidays of 2026. If the last day of school falls in an even week and the “even weeks” parent also has the first half of the summer holidays, the child stays with the same parent for an extended period. Anticipating this overlap avoids last-minute tensions.
The most reliable method is to establish, as early as September, an annual schedule that integrates both the week numbers and the exact dates of each holiday period by zone. Note the responsible parent for each block, then check the transitions.
Exchange day and shared custody 2026: choosing the right time slot
The exchange day conditions the entire functioning of the alternation. Friday evening after school remains the most common choice, but it is not always the most suitable. Feedback varies on this point, as logistics depend on the distance between the two homes and school organization.
An exchange on Monday morning at school has a concrete advantage: the child leaves one home and arrives at school, not at the other parent’s. The transition occurs at a neutral location, which reduces friction between adults. The “outgoing” parent drops off the child, and the “incoming” parent picks them up in the evening.
Public holidays and bridges in 2026
The year 2026 places several public holidays in the middle of the week. When a public holiday falls during a parent’s week, the question of the “bridge” arises. The standard judgment generally does not provide for bridges, leaving room for negotiation or conflict.
- May 1, 2026, falls on a Friday: if the exchange occurs on Friday evening, an appropriate time must be agreed upon or postponed to Saturday morning
- Ascension Thursday can create a four-day extended weekend: check in the judgment if this bridge is treated as a “short holiday” or as an ordinary weekend
- July 14, 2026, falls in the middle of the summer period: it is the summer holiday sharing that applies, not the weekly alternation
Drafting the judgment and even/odd calendar: what recent case law requires
Since 2024, the Court of Cassation has tightened its requirements regarding the precision of decisions establishing shared residence. A judgment that merely states “one week out of two” without specifying the starting week number, the day and time of transition, or the functioning during holidays, can be more easily contested before the judge.
For parents negotiating an amicable agreement or appearing before the family court judge in 2026, this evolution requires drafting a precise text. The number of the first week assigned to each parent, the exact day and time of the exchange, and the mechanism applicable when the year has 53 weeks must be indicated.
In Paris and Île-de-France, the weekly alternation structured on the even/odd model has become the majority format when logistical conditions allow. This is not a universal model: the geographical proximity between the two homes and the school remains the determining criterion for the judge.
The even and odd week calendar is just a tool. Its reliability entirely depends on the precision of the legal text that underpins it and the ability of both parents to read it the same way. When doubt arises about the interpretation, a simple timestamped written exchange often suffices to defuse the conflict before it reaches court.
