Returns a number that indicates where the week falls numerically within a year.
The WEEKNUM function considers the week containing January 1 to be the first week of the year. However, there is a European standard that defines the first week as the one with the majority of days (four or more) falling in the new year. This means that for years in which there are three days or less in the first week of January, the WEEKNUM function returns week numbers that are incorrect according to the European standard.
Dates should be entered by using the DATE function, or as results of other formulas or functions. For example, use =DATE(2008,5,23) for the 23rd day of May, 2008. Problems might occur if dates are entered as text.
A date within the week.
A number that determines on which day the week begins. The default is 1.
Excel stores dates as sequential serial numbers so they can be used in calculations. By default, January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900.
To make the following example easier to understand, you can copy the data to a blank sheet and then enter the function underneath the data. Do not select the row or column headings (1, 2, 3... A, B, C...) when you copy the sample data to a blank sheet.
|Note March 9, 2008 is a Sunday.|