Excel WEEKNUM | ComExcelHub

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WEEKNUM: WEEKNUM is a date and Time function in Excel. Using WEEKNUM function, if we input any date we get week number in that year.

Syntax of Excel WEEKNUM Function

WEEKNUM(serial_number,[return_type])

1st Argument: serial_number this is a Compulsory argument

2nd Argument: [return_type] this is a optional argument

Explanation of Arguments in Excel WEEKNUM Function

serial_number: Under this argument, we need to give a date or select any cell which has a date.

[return_type]: Under this argument, we have the option to select the week to begin the day like Sunday, Monday… The default value is 1 which is Sunday.

Please refer to the below table for more information on return_type.

In WEEKNUM Function there are two systems used :

System 1 The week containing January 1 is the first week of the year, and is numbered week 1.
System 2 The week containing the first Thursday of the year is the first week of the year and is numbered as week 1. This system is the methodology specified in ISO 8601, which is commonly known as the European week numbering system.
For More Info on ISO Week number Click Here.
In General, System2 is not used on day to day Excel work.