The WEEKNUM function in Excel takes a date and returns a week number (1-54) that corresponds to the week of year. WEEKNUM Function counts week starting with January 1 as first week.
Syntax for WEEKNUM Function in Excel
serial_number – The date for which you want to get the week number.
return_type – [optional], The day at which the week begins. Default is 1
Example of WEEKNUM Function in Excel
WEEKNUM Function with default return_type or return_type =1
When Return type =1, Week number is calculated by keeping Sunday as first day of the week and Saturday as last day of week.
WEEKNUM Function with return_type =2
When Return type =2, Week number is calculated by keeping Monday as first day of the week and Sunday as last day of week