Week 40 of the year
When is week 40? The exact Monday–Sunday dates of ISO week 40 for every year from 2024 to 2032.
Week 40 of 2026 runs from Monday, Sep 28, 2026 to Sunday, Oct 4, 2026 (Sep / Oct). Week 40 of 2026 is 11 weeks away. ISO week code: 2026-W40.
Week 40 dates by year
| Year | Week 40 starts (Mon) | Week 40 ends (Sun) | Month |
|---|---|---|---|
| 2024 | Monday, September 30, 2024 | Sunday, October 6, 2024 | Sep / Oct |
| 2025 | Monday, September 29, 2025 | Sunday, October 5, 2025 | Sep / Oct |
| 2026 | Monday, September 28, 2026 | Sunday, October 4, 2026 | Sep / Oct |
| 2027 | Monday, October 4, 2027 | Sunday, October 10, 2027 | October |
| 2028 | Monday, October 2, 2028 | Sunday, October 8, 2028 | October |
| 2029 | Monday, October 1, 2029 | Sunday, October 7, 2029 | October |
| 2030 | Monday, September 30, 2030 | Sunday, October 6, 2030 | Sep / Oct |
| 2031 | Monday, September 29, 2031 | Sunday, October 5, 2031 | Sep / Oct |
| 2032 | Monday, September 27, 2032 | Sunday, October 3, 2032 | Sep / Oct |
All weeks
Frequently asked questions
What month is week 40 in?
Week 40 typically falls in October. The exact dates shift by up to a few days from year to year because week 1 is anchored to January 4, not January 1.
How do I write week 40 as a week code?
The ISO code is the year plus W40 — for example 2026-W40, short form 26W40, or YYWW date code 2640. See week number formats.
Are these dates the same in every country?
Yes for ISO 8601 (Monday-start) numbering, which is what this table shows. US Sunday-start calendars can label the same days with a number one higher — see week start conventions.