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Week Number
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Year
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Day of Year
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Quarter
All Weeks of
| Week | Start Date | End Date | Quarter |
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Frequently Asked Questions
What is an ISO week number?
ISO week numbers follow the ISO 8601 standard. Week 1 is the week containing the first Thursday of the year. Weeks run Monday to Sunday. Most countries use this standard for business and project planning.
What week number is it this week?
The current week number is shown automatically at the top of the page every time you visit. It updates daily.
How many weeks are in a year?
Most years have 52 weeks. Some years have 53 ISO weeks — this happens when January 1st falls on a Thursday, or in leap years when it falls on a Wednesday.