The Standard For Business Planning
If you work in manufacturing, logistics, or agile software development, you've likely encountered schedules based on week numbers rather than specific calendar dates. Our calculator uses the strict ISO 8601 standard to ensure your week numbers align perfectly with international business standards.
Find the exact start and end dates
Not only does this tool tell you the current week number, but it also automatically calculates the exact Monday on which the week begins and the Sunday on which it ends. This takes the guesswork out of sprint planning and reporting.
Frequently Asked Questions
The ISO week date system is part of the ISO 8601 date and time standard used by businesses and governments worldwide. In this system, weeks strictly start on Monday.
Most years have exactly 52 weeks. However, because a year has 365 (or 366) days, which is slightly more than 52 full weeks, there are occasional "leap weeks" resulting in a 53-week year.
Week numbers (e.g., W12, W45) are crucial in corporate environments for project sprints, manufacturing schedules, and accounting periods because they provide a standardized, evenly-sized chunk of time compared to irregular calendar months.