Week Number Finder is now live on Tools.Town — a tool that tells you the ISO 8601 week number for any date, and the Monday-to-Sunday date range for any week number you specify — useful for project planning, financial reporting, and calendar-based scheduling.
What week is November 15th? What dates are in Week 47? Now you’ll always know.
What Does It Do?
Date → Week
Enter any date and get its ISO week number, the week's start (Monday) and end (Sunday) dates.
Week → Dates
Enter a year and week number to find the exact date range — Monday through Sunday — for that week.
Current Week
The current week number is displayed on load — always know what week it is without counting.
Uses ISO 8601 week numbering — weeks start on Monday and week 1 is the week containing the year’s first Thursday. This is the European and international business standard.
How It Works
Pick a date
Select any date from the date picker or type it in. The week number appears instantly.
Or enter a week
Type a year and week number to find the corresponding Monday–Sunday date range.
Copy result
Copy the week number, the date range, or both for use in your reports or planning docs.
Why We Built It
Week numbers appear in project plans, sprint tracking, financial reports, and payroll systems — but not on most calendar apps. When someone says “deliver by Week 47,” you need a quick way to map that to a calendar date range. Week Number Finder makes that lookup instant in both directions.
Try It Now
Week Number Finder
Get the ISO week number for any date, or the date range for any week number. Bidirectional, instant.
Also useful: Date Calculator, Business Days Calculator, and more date tools.
Related Posts
Frequently Asked Questions
What week numbering standard does it use?
Why might a date in January be in week 52 or 53?
Can I look up which dates are in a specific week number?
Explore more on Tools.Town Blog
Finance guides, tool launches, and engineering stories — updated weekly.