About
About WeekYear
What WeekYear is
WeekYear is a small, single-purpose web utility built around one question: what week is it right now, by ISO 8601 rules? The homepage shows the current ISO week number, the Monday-to-Sunday range, and the percentage of the year completed. From there, two companion pages extend the toolset: a date-to-week converter with a deep guide to ISO 8601, and a printable 52-row year-in-weeks calendar for productivity planning.
The site is intentionally narrow. It does not try to be a general calendar app or a project-management tool. It does one thing: turn dates into precise, shareable week numbers, and present the year as a structure you can plan against.
Who it is for
WeekYear is built for anyone who works in weeks. That includes operations and logistics teams who schedule by ISO week codes, product and engineering teams running sprint cadences, content and marketing teams planning publication weeks, finance teams reconciling weekly closes, and individuals who use weekly reviews to track personal goals. It is also useful for international collaborators who need a common reference that does not depend on the US-vs-Europe convention of when a week starts.
What it covers
- The current ISO 8601 week number and week range, updated live in the browser.
- A date-to-week converter with the full ISO week year and ISO week code.
- A printable year-in-weeks grid for any year between 1900 and 2100.
- Practical guides to ISO 8601 rules, edge cases, and week-based planning.
- Code samples for Python, JavaScript, and Excel for developers who need to compute ISO weeks themselves.
Editorial approach
Guides are written to be accurate first and useful second. The goal is to explain ISO 8601 in plain language without skipping the rules that matter (the Thursday rule, the 53-week years, the gap between calendar year and ISO week year). Where there are common misconceptions — for example, that week numbers always reset on January 1 — they are addressed directly rather than glossed over.
Pages avoid invented case studies, fabricated statistics, and trend-of-the-year framing. Examples are kept generic so they remain correct over time. When something cannot be stated with confidence, it is left out.
How content is produced
All calculations on the site run client-side using ISO 8601 algorithms documented on the ISO 8601 guide. Written content is drafted, reviewed, and revised against the standard itself rather than copied from third-party summaries. Pages are reviewed periodically for accuracy and clarity, and the "Last reviewed" line on substantive pages reflects the most recent check.
Independence
WeekYear is an independent project. It is funded by display advertising served through Google AdSense; details about ad cookies and personalization are described in the Privacy Policy and Cookie Policy. The site does not accept paid placements inside guides, and links to external resources are editorial choices, not paid partnerships.
Get in touch
Corrections, technical questions about the ISO calculations, or suggestions for new guides are welcome. See the Contact page for the best way to reach the site.