What Is a Week Number?
A week number represents the specific week of the year.
In the ISO 8601 calendar, in which weeks start with Monday and end on Sunday, there are approximately 52 weeks in a year. According to this week numbering system, the first week of the year (Week 1) contains the first Thursday.
However, since a year has 365 days (366 in leap years), some years may include a 53rd week. This happens when January 1 falls on a Thursday in a regular year, or on a Wednesday in a leap year.
What Is the Week Number Page?
On this week number page, you can do many operations related to week numbers.
- View the current week number and its date range (when the week starts and ends)
- Find the number of the week for a specific date (date to week number conversion)
- See the date range for any week number in a specific year (week number to date conversion)
Note: The page updates every minute to provide you with the most accurate information. If you check our online clock page and observe when the clock hits 00:00 on Monday (the beginning of the new week), you will see that the numbers here will update within a minute.
How to Use the Week Number Calculator
Find out what week of the year it is
- Switch to "Current Week Number" tab, which is the default tab when you visit the page.
- You will see the number of the week and its corresponding date range.
- You can also see how many weeks are left in this year.
Convert date to week number
- Switch to "Date to Week Number" tab.
- Click the "Date" input to open the calendar and select a date.
- Click the "Convert to Week Number" button.
- You will see which week number corresponds to your selected date.
Convert week number to date
- Switch to "Week Number to Date" tab.
- Enter the number of the week for conversion (1 for first week, up to 53)
- Enter the year (defaults to current year).
- Click the "Convert to Date" button.
- You will see the date range for your selected week.