ISO 8601 · 2026

What week is it?

Today's ISO 8601 week number, updated live, plus whether it's an odd or an even week – handy for two-week (week A / week B) school timetables.

Right now it is

Week 43

odd

19 October – 25 October 2026

Week 43 of 53 in 2026

Plan ahead

The next weeks

  1. 4426 October – 1 Novembereven
  2. 452 November – 8 Novemberodd
  3. 469 November – 15 Novembereven
  4. 4716 November – 22 Novemberodd
  5. 4823 November – 29 Novembereven
  6. 4930 November – 6 Decemberodd
  7. 507 December – 13 Decembereven
  8. 5114 December – 20 Decemberodd
All 53 weeks of 2026
WeekDatesType
129 December – 4 January 2026odd
25 January – 11 January 2026even
312 January – 18 January 2026odd
419 January – 25 January 2026even
526 January – 1 February 2026odd
62 February – 8 February 2026even
79 February – 15 February 2026odd
816 February – 22 February 2026even
923 February – 1 March 2026odd
102 March – 8 March 2026even
119 March – 15 March 2026odd
1216 March – 22 March 2026even
1323 March – 29 March 2026odd
1430 March – 5 April 2026even
156 April – 12 April 2026odd
1613 April – 19 April 2026even
1720 April – 26 April 2026odd
1827 April – 3 May 2026even
194 May – 10 May 2026odd
2011 May – 17 May 2026even
2118 May – 24 May 2026odd
2225 May – 31 May 2026even
231 June – 7 June 2026odd
248 June – 14 June 2026even
2515 June – 21 June 2026odd
2622 June – 28 June 2026even
2729 June – 5 July 2026odd
286 July – 12 July 2026even
2913 July – 19 July 2026odd
3020 July – 26 July 2026even
3127 July – 2 August 2026odd
323 August – 9 August 2026even
3310 August – 16 August 2026odd
3417 August – 23 August 2026even
3524 August – 30 August 2026odd
3631 August – 6 September 2026even
377 September – 13 September 2026odd
3814 September – 20 September 2026even
3921 September – 27 September 2026odd
4028 September – 4 October 2026even
415 October – 11 October 2026odd
4212 October – 18 October 2026even
4319 October – 25 October 2026odd
4426 October – 1 November 2026even
452 November – 8 November 2026odd
469 November – 15 November 2026even
4716 November – 22 November 2026odd
4823 November – 29 November 2026even
4930 November – 6 December 2026odd
507 December – 13 December 2026even
5114 December – 20 December 2026odd
5221 December – 27 December 2026even
5328 December – 3 January 2027odd

How are week numbers counted?

Most of Europe and many schools use ISO 8601 week numbers. Weeks run Monday to Sunday, and week 1 is the week that contains the year's first Thursday. That's why the first days of January can still belong to week 52 or 53 of the previous year.

Note: the US often uses a different system where weeks start on Sunday, so its week numbers can differ by one around New Year. If your school calls ISO-odd weeks "week B", tick "My school counts the other way round".

Week A / week B on your phone

Let your timetable know which week it is

Lekto counts odd and even weeks automatically and only shows the lessons you have this week – in the app and on the widget.

  • Lessons every week, even weeks only or odd weeks only
  • Flip the parity with one switch
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How week A / week B works in Lekto
Let your timetable know which week it is

FAQ

What week is it?

What week number is it today?

The current ISO week number is shown at the top of this page and updates live.

Is this week odd or even?

If the week number is even, it's an even week; if it's odd, it's an odd week. Schools that use week A / week B sometimes count differently, so follow your school's announcement.

How many weeks are in a year?

A year has 52 or 53 ISO weeks. Years where 1 January is a Thursday (or a Wednesday in a leap year) have 53.

Why is 1 January sometimes in week 52 or 53?

ISO week 1 is the week with the first Thursday of the year, so days before that Monday belong to the last week of the previous year.

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