ISO Week Number Calculator
Find the exact ISO 8601 week number for any date.
Frequently Asked Questions
What is an ISO week?
The ISO 8601 week date system specifies that weeks start on Monday, and the first week of the year is the one that contains the first Thursday of the year.
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Calculate the number of working days between two dates.
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Business Day
A business day represents a working day, typically Monday through Friday, excluding weekends and public holidays.