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1Introduction
Date Week Number Calculator is a convenient tool for determining the week number of a date in a year. It follows the ISO 8601 standard, where Monday is the start of the week, and the first week of each year contains the first Thursday of that year. Simply enter a date to get the week number (1-53) and the start and end dates of that week. In addition, the tool provides customization options, allowing you to choose the start day of the week (Monday or Sunday) to accommodate different regional habits.
2How to Use
Input Date
Enter a date in the input box, format YYYY-MM-DD.
Select Week Start Day
According to your needs, select whether the week starts on Monday or Sunday (Monday is default).
Click Calculate
Click the 'Calculate Week Number' button, and the output will display the week number and the date range of that week.
3FAQ
What is ISO week number?
The ISO 8601 standard defines that the first week of a year is the week containing the first Thursday of that year, with Monday as the start of the week. This tool uses this standard by default.
How to customize the start day of the week?
Select Monday or Sunday as the first day of the week in the dropdown menu, then calculate.
