About the Date to Week Number Tool
How to use the date to week number tool?
Want to know what week number it is today? Just enter the date and our tool will automatically calculate and display what week of the year it is.
Supports checking what week number it is today, how many weeks in a year, what week of the year today is, and other common questions.
Whether you want to check what week number it is today or batch check multiple dates, we can provide quick and accurate results.
Using our date to week number tool is very simple:
- Enter the date in the input box, supports multiple formats
- Click the calendar icon to select a date
- The system automatically calculates and displays results
- View week number comparisons under different standards
- Copy results or share with others
What date formats are supported?
This tool supports multiple common date formats:
- Standard format: 2025-12-02
- Slash format: 2025/12/02
- Dot format: 2025.12.02
- Chinese format: 2025年12月2日
- Short format: 12-02-2025
Week Number Calculation Standards Explanation
ISO 8601 Standard
International standard, each week starts on Monday, the first week contains the first Thursday. Suitable for Europe, Asia and other regions.
US Standard
Each week starts on Sunday and ends on Saturday. The first week starts counting from January 1st.
Simple Standard
Fixed 52 weeks per year, remaining days are counted in the last week. Simple calculation but not precise.