Find the Week Number for Any Date
What week of the year is it? Enter any date and get its ISO 8601 week number instantly. Whether you're scheduling sprints, tracking payroll periods, or filing weekly reports, this tool keeps you aligned.
How to Use the Week Number Calculator
1
Enter a date or use today's date as the default.
2
The ISO week number is displayed immediately.
3
Use it for sprint planning, reports, or scheduling.
Frequently Asked Questions
What is an ISO week number?
ISO 8601 defines weeks starting on Monday. Week 1 is the week containing the first Thursday of the year, ensuring consistent international numbering.
How many weeks are in a year?
Most years have 52 weeks, but some years (called long years) have 53 weeks under the ISO system.
Does this follow the US or European convention?
It follows the ISO 8601 international standard. In the US, weeks often start on Sunday, which may produce different week numbers.