About WeekNumber.info
Welcome to WeekNumber.info, your trusted resource for printable calendars and week number lookup information. Our mission is to provide users around the globe with accurate, up-to-date, and easy-to-access information. Whether you're looking for a specific calendar year or need to find out the week number, WeekNumber.info is here to help.
Our Mission
At WeekNumber.info, we strive to deliver the most comprehensive and reliable calendar and week number data available. Our goal is to make sure that anyone, anywhere, can quickly and easily find the information they need.
What We Offer
Our website offers a wide range of resources, including:
- Printable Calendars: Download printable calendars in PDF format for years ranging from 1900 to 2100. Choose between USA and EU/ISO formats to suit your needs.
- Week Number Lookup: Access accurate and comprehensive week number data, including start and end dates, for any given week.
Our Commitment
We are committed to continually improving WeekNumber.info to better serve our users. We value your feedback and are always looking for ways to enhance our services. If you have any suggestions or comments, please don't hesitate to reach out to us.
Contact Us
If you have any questions, feedback, or need assistance, feel free to contact us. Our dedicated support team is here to help you with any inquiries you may have.
Thank you for choosing WeekNumber.info as your go-to resource for printable calendars and week number lookup information. We appreciate your trust and support, and we look forward to continuing to serve you.
How week numbers are counted
Most of the world numbers weeks according to the ISO 8601 standard. A week starts on Monday, and week 1 is the week that contains the first Thursday of the year, which is always the week that contains 4 January.
Week 1 of 2026 began on December 29, 2025. 2026 has 53 ISO weeks, because 1 January 2026 falls on a Thursday.
Because of this rule, the first days of January can belong to the last week of the previous year, and the last days of December can belong to week 1 of the next year.
In the United States, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the US week number can differ from the ISO week number.
Frequently Asked Questions (FAQ)
What is WeekNumber.info?
WeekNumber.info is a comprehensive resource for printable calendars and week number lookup. We provide accurate, up-to-date information for users around the world, helping them access the tools and data they need quickly and easily.
What is week number lookup?
Week number lookup allows you to find the specific week number for any given date, as well as the start and end dates of a particular week. You can use this tool to plan events, track deadlines, or simply stay organized.
Why do the US and Europe show different week numbers?
Europe follows ISO 8601: weeks start on Monday and week 1 is the week with the first Thursday of the year. In the US, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the two numbers can differ by one.
Which formats are the calendars available in?
Our calendars are available in A4 printable PDF format. We offer both USA and EU/ISO versions to accommodate different preferences and standards.
Is there a cost to use WeekNumber.info?
No, WeekNumber.info is completely free to use. You can access and download all the resources available on our site without any charge.