Runs locally
ISO Week Number
The ISO week of a civil date.
Ctrl+Enter runs. Ctrl+Shift+Backspace clears.
Export and import are available after you sign in. Sign in
The ISO week of a civil date. Runs in the browser. Nothing is uploaded.
About this tool
Find which ISO week a date falls in, for planning, reports or sprint numbering. Enter a date and get its week number under ISO 8601.
How to use it
- 01
Enter the date.
- 02
Read the ISO week number.
- 03
Use it in reports or calendars.
FAQ
Frequently asked questions
How is the ISO week defined?
Weeks start on Monday, and week 1 is the week that contains the first Thursday of the year.
Can a year have 53 weeks?
Yes. Some years have an ISO week 53, and early January dates can belong to the last week of the previous year.