Week Number 40 of the current year 2023 is defined as follows.
European and Asian calculation
Mainly in Europe and Asia, the international ISO 8601 definition is used for counting calendar weeks:
American calculation
In the USA, Canada and most Latin American countries, Australia, Japan, Israel, South Korea and others, the following definition of Week 40 applies:
The date of the calendar Week 40 and other years
The following table provides an overview of the calendar Week 40 for each year. The beginning of the calendar Week 40 and its end are shown according to the two most commonly used definitions of calendar weeks worldwide. The first is the international ISO standard for Week 40, referred to here as the "European" calculation method. It is mainly used in Europe and Asia. On the other hand, the "American" calculation method for weeks is listed, which is mainly used in North and South America, Australia and Japan.
| Week Number 40 | ||||
|---|---|---|---|---|
| Year |
Calculation Method | Start of Week 40 | End of Week 40 | ISO Name |
| 2020 | European | Monday, September 28, 2020 | Sunday, October 4, 2020 | 2020‑W40 |
| American | Sunday, September 27, 2020 | Saturday, October 3, 2020 | - | |
| 2021 | European | Monday, October 4, 2021 | Sunday, October 10, 2021 | 2021‑W40 |
| American | Sunday, September 26, 2021 | Saturday, October 2, 2021 | - | |
| 2022 | European | Monday, October 3, 2022 | Sunday, October 9, 2022 | 2022‑W40 |
| American | Sunday, September 25, 2022 | Saturday, October 1, 2022 | - | |
| 2023 | European | Monday, October 2, 2023 | Sunday, October 8, 2023 | 2023‑W40 |
| American | Sunday, October 1, 2023 | Saturday, October 7, 2023 | - | |
| 2024 | European | Monday, September 30, 2024 | Sunday, October 6, 2024 | 2024‑W40 |
| American | Sunday, September 29, 2024 | Saturday, October 5, 2024 | - | |
| 2025 | European | Monday, September 29, 2025 | Sunday, October 5, 2025 | 2025‑W40 |
| American | Sunday, September 28, 2025 | Saturday, October 4, 2025 | - | |
| 2026 | European | Monday, September 28, 2026 | Sunday, October 4, 2026 | 2026‑W40 |
| American | Sunday, September 27, 2026 | Saturday, October 3, 2026 | - | |
Determine Week 40 or other calendar weeks in the calculator
In the Calendar Week Calculator, the entry for the European ISO calendar Week 40 is preset. Of course, you can also enter other values here to determine the date of the beginning of the week or the end of the week.
Calendar Week Calculator for other years
For calendar years further back or in the future, you will find the beginning and end of the corresponding calendar week in the Calendar Week Calculator.
Source information
As source for the information in the 'Week Numbers' category, we have used in particular:
Last update on June 3, 2023
The pages of the 'Week Numbers' category were last editorially reviewed by Michael Mühl on June 3, 2023. They all correspond to the current status.
Previous changes on June 25, 2021
- Publication of the Week Number Calculator
- Editorial revision of all texts in this category