WEEKNUM Function Explained
The WEEKNUM Function in Microsoft Excel returns the week number of a given date. It takes two arguments: a date and an optional return type. The date argument is required and must be entered as a valid Excel date. The return type argument is optional and can be either 1 or 2. If the return type is 1, the week number returned is based on the ISO standard, where the first week of the year is the week that contains the first Thursday of the year. If the return type is 2, the week number returned is based on the U.S. standard, where the first week of the year is the week that contains January 1.
WEEKNUM Function Syntax
WEEKNUM(serial_number, [return_type])
- serial_number: The date of the week you want to find the number of. This can be entered as a date, a text string, or a reference to a cell containing a date.
- return_type: (optional) The type of week numbering you want to use. 1 = Week starts on Sunday, 2 = Week starts on Monday.