Current week number
Week numbers. Dates. A little more clarity.
31 August 2026 – 6 September 2026
ISO 8601 · Monday–Sunday
September 2026
| Week | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|---|
| 36 | |||||||
| 37 | |||||||
| 38 | |||||||
| 39 | |||||||
| 40 |
Which week is this date?
Choose a date to find its ISO week number.
Year overview 2026
| Week | From (Mon) | To (Sun) |
|---|---|---|
| 01 | ||
| 02 | ||
| 03 | ||
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| 18 |
| Week | From (Mon) | To (Sun) |
|---|---|---|
| 19 | ||
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| 34 | ||
| 35 | ||
| 36 |
| Week | From (Mon) | To (Sun) |
|---|---|---|
| 37 | ||
| 38 | ||
| 39 | ||
| 40 | ||
| 41 | ||
| 42 | ||
| 43 | ||
| 44 | ||
| 45 | ||
| 46 | ||
| 47 | ||
| 48 | ||
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| 50 | ||
| 51 | ||
| 52 | ||
| 53 |
How are week numbers counted?
ISO 8601 weeks start on Monday and end on Sunday. Week 1 contains 4 January. A week year has 52 or 53 weeks.
What happens at New Year?
A date in early January can belong to the last week of the previous week year. Late December can already be part of week 1 of the next week year.
Week calendars for planning
What does a calendar week tell you?
A week number identifies a Monday-to-Sunday period in a week year. It is useful for delivery dates, work schedules, school timetables and project planning. Always include the week year when sharing dates around New Year.
Is ISO week numbering used everywhere?
This site uses ISO 8601 in both languages. Other calendars may start weeks on Sunday or count the week containing 1 January as week 1. Check the convention used by your organisation before comparing week numbers.
The initial date uses Europe/Zurich. With JavaScript enabled, today follows your device’s local date.