Week Number Calculator
Calculate which week of the year a specific date falls in.
Frequently Asked Questions
How is the week number calculated?
The week number is calculated according to the ISO 8601 standard. Under this standard, the first week of the year is the week containing the first Thursday of the year. Weeks start on Monday.
How many weeks are there in a year?
There are usually 52 weeks in a year. However, some years may have 53 weeks. This depends on which day the first day of the year falls on.
What is the ISO 8601 week standard?
ISO 8601 is the international standard for dates and times. Under this standard, weeks start on Monday, and the first week of the year is the week that has at least 4 days in the new year.
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