Week 53 in 2026: two odd weeks in a row
Yes, 2026 has a week 53. It runs from Monday 28 December 2026 to Sunday 3 January 2027, and it is an odd week. Because week 1 of 2027 is odd too, you get two odd weeks back to back. If your shared custody schedule is based on even and odd weeks, now is a good time to agree on how to handle it.
Why do some years have 53 weeks?
Week numbers follow the ISO 8601 standard, used across Europe and in most business and school calendars: weeks start on Monday, and week 1 is the week that contains the first Thursday of January (equivalently, the week that contains 4 January).
A normal year is 52 weeks and 1 day long; a leap year is 52 weeks and 2 days. Those spare days add up, and roughly every five or six years they make a whole extra week. In practice, an ISO year is a 53-week year when:
- it starts on a Thursday (2026 does: 1 January 2026 was a Thursday), or
- it is a leap year starting on a Wednesday (like 2020).
Since 31 December 2026 is also a Thursday, the whole week of 28 December still belongs to 2026: that is week 53. Week 1 of 2027 only starts on Monday 4 January 2027.
Note that some calendar apps set to US conventions (weeks starting on Sunday) number weeks differently. If in doubt, check a date with our even or odd week checker, which uses ISO 8601.
The result: two odd weeks in a row
Normally the pattern alternates neatly: week 52 (even), then week 1 (odd). With a week 53, the number 53 is odd and the week 1 that follows is odd as well, so parity skips a beat between 2026 and 2027. In the table, the "odd-week parent" is the one who usually has the children in odd weeks:
| Week | Dates | Parity | Strict parity: children with… | Continuous alternation: children with… |
|---|---|---|---|---|
| 51 | 14 – 20 Dec 2026 | Odd | Odd-week parent | Odd-week parent |
| 52 | 21 – 27 Dec 2026 | Even | Even-week parent | Even-week parent |
| 53 | 28 Dec 2026 – 3 Jan 2027 | Odd | Odd-week parent | Odd-week parent |
| 1 | 4 – 10 Jan 2027 | Odd | Odd-week parent (2nd week running) | Even-week parent |
| 2 | 11 – 17 Jan 2027 | Even | Even-week parent | Odd-week parent |
If you apply parity strictly and hand over on Mondays, the odd-week parent has the children for 14 days in a row, from Monday 28 December 2026 to Sunday 10 January 2027. The even-week parent, on the other hand, goes two weeks without them: after week 52, they next have the children on Monday 11 January 2027 (week 2). Over 2026 as a whole there are 27 odd weeks and 26 even weeks.
What week 53 means for shared custody
Many parenting plans and court orders simply say "even weeks with Dad, odd weeks with Mum" (or the other way round) and never mention week 53. There are several sensible ways to deal with it:
1. Follow the week numbers to the letter
The odd-week parent keeps the children for week 53 and week 1. It matches the wording of the agreement, it is easy to explain, and the even/odd rule stays the same in 2027. The downside: one parent gets two weeks in a row and the other misses two.
2. Keep alternating week by week
Ignore the numbers and just keep swapping: week 53 with the odd-week parent, week 1 with the even-week parent, and so on. The children's rhythm is unchanged, but the even/odd mapping flips for the whole of 2027: from January 2027, the parent who had even weeks now has odd weeks, and vice versa. That lasts until the next week 53, at the end of 2032. Remember to tell the school, childminder and anyone using a shared calendar.
3. Split week 53 in half
A middle ground: each parent takes half of week 53 (for example Monday 28 to Thursday 31 December for one, Friday 1 to Sunday 3 January for the other), then the usual parity resumes in week 1. Both parents keep their familiar weeks for 2027.
4. Check your parenting plan or court order
Read what your agreement actually says: some include a start date or an explicit rule that settles the question. Whatever you choose, the safest approach is to agree in advance and in writing (an email or a text message is often enough to keep a record). If you cannot agree, a family mediator or solicitor can help: this page offers practical pointers, not legal advice.
What about the Christmas holidays?
In 2026, week 53 falls in the middle of the Christmas holidays: many UK schools break up around 18–19 December 2026 and go back on Monday 4 January 2027 (dates vary by local authority). During the break, your holiday-sharing arrangement usually takes over anyway. But the question does not go away: it moves to the first week of January. On Monday 4 January, week 1 is odd, straight after an odd week 53, so decide before the holidays who has the children that day.
Handle the exception in the app
The Even / Odd iPhone app lets you add custody exceptions: you set who has the children for a specific period (week 53, the Christmas holidays…) without changing your regular alternation. The widget then shows the right parent.
Discover the appThe next 53-week years
The last week 53 was in 2020 (28 December 2020 to 3 January 2021). After 2026, the next ones are:
- 2032: Monday 27 December 2032 to Sunday 2 January 2033 (a leap year starting on a Thursday)
- 2037: Monday 28 December 2037 to Sunday 3 January 2038
- 2043: Monday 28 December 2043 to Sunday 3 January 2044
- 2048: Monday 28 December 2048 to Sunday 3 January 2049 (a leap year starting on a Wednesday)
- 2054: Monday 28 December 2054 to Sunday 3 January 2055
If you are drafting or reviewing a parenting plan, it is worth adding one sentence about week 53: it will come round several times before your children grow up.
Week 53: frequently asked questions
Is there a week 53 in 2026?
Is week 53 even or odd?
Who has the children in week 53 with week-on/week-off custody?
How long does the even-week parent go without the children?
Why do some years have 53 weeks?
When is the next 53-week year?
The Even / Odd app for iPhone
A widget keeps the current week on your home screen. Free, offline, no ads.
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