weekyear - script and chart function
This function returns the year to which the week number belongs according to ISO 8601. The week number ranges between 1 and approximately 52.
Syntax:
weekyear(expression)
Return data type: integer
Limitations:
Some years, week #1 starts in December, e.g. December 1997. Other years start with week #53 of previous year, e.g. January 1999. For those few days when the week number belongs to another year, the functions year and weekyear will return different values.