Week 40 2023

Week 40 2023
Week Number 40 in 2023

Week Numbers ﹣ Week 40 2023

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:

Monday, October 2, 2023 – Sunday, October 8, 2023

ISO: 2023‑W40
Week Number 2023

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:

Week Number 40/2023

Sunday, October 1, 2023

Saturday, October 7, 2023


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
Start of Week 40End of Week 40ISO Name
2020 European Monday, September 28, 2020Sunday, October 4, 20202020‑W40
American Sunday, September 27, 2020Saturday, October 3, 2020-
2021 European Monday, October 4, 2021Sunday, October 10, 20212021‑W40
American Sunday, September 26, 2021Saturday, October 2, 2021-
2022 European Monday, October 3, 2022Sunday, October 9, 20222022‑W40
American Sunday, September 25, 2022Saturday, October 1, 2022-
2023 European Monday, October 2, 2023Sunday, October 8, 20232023‑W40
American Sunday, October 1, 2023Saturday, October 7, 2023-
2024 European Monday, September 30, 2024Sunday, October 6, 20242024‑W40
American Sunday, September 29, 2024Saturday, October 5, 2024-
2025 European Monday, September 29, 2025Sunday, October 5, 20252025‑W40
American Sunday, September 28, 2025Saturday, October 4, 2025-
2026 European Monday, September 28, 2026Sunday, October 4, 20262026‑W40
American Sunday, September 27, 2026Saturday, 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