How it works
Find the ISO week and week-year. Dates near New Year can belong to the preceding or following ISO year.
Inputs and units
| Input | Example value | What to enter |
|---|---|---|
| Calendar date | October 8, 2026 | Choose a valid calendar date. |
Worked example
Show example inputs and results
This example is generated by the same calculation engine using the starting values in the form. Your own inputs produce your own result.
- Calendar date
- October 8, 2026
Complete example results
- ISO week
- 41
- ISO year
- 2,026
Reading the result
Elapsed calendar time differs from completed years or months. Check interval endpoints, leap-year conventions and any working-day scope.
Questions and answers
Can I use the example values for my own calculation?
The example values illustrate the calculation. Replace every input with your own information, especially dates, rates and the selected operation.
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.