Documentation/Calc Functions/ISOWEEKNUM

Function name:
ISOWEEKNUM

Category:
Date and Time

Summary:
Determines the international standard ISO 8601 week number in which a specified date lies.

Syntax:
ISOWEEKNUM(Date)

Returns:
Returns a positive integer in the range 1 to 53 which is the ISO 8601 week number in which the specified date lies.

Arguments:
Date is the date (in quotation marks) or a date-time serial number, or a reference to the cell containing one of those types, for which the calculation is to be carried out.


 * If Date does not contain a valid date expression, then ISOWEEKNUM reports a #VALUE! error.
 * ISOWEEKNUM ignores any time components of Date.

Details specific to ISOWEEKNUM function
The International Organization for Standardization’s ISO 8601 defines that Monday is the first day of the week. A week that lies partly in one year and partly in another year is assigned a number in the year in which most of its days lie. That means that week number 1 of any year is the week that contains January 4.

Visit Wikipedia’s ISO week date page for more information.

Related LibreOffice functions:
DAY

MONTH

WEEKDAY

WEEKNUM

YEAR

ODF standard:
Section 6.10.11, part 2

Equivalent Excel functions:
ISOWEEKNUM