VECKONR
VECKONR beräknar veckonumret i året för det interna datumvärdet.
Enligt den internationella ISO-standarden ISO 8601 ska måndag räknas som veckans första dag. En vecka som sträcker sig över ett årsskifte tilldelas ett nummer i det år då merparten av veckans dagar infaller. Det innebär att vecka 1 ett givet år alltid är den vecka då den 4 januari infaller.
This function is part of the Open Document Format for Office Applications (OpenDocument) standard Version 1.2. (ISO/IEC 26300:2-2015)
ISOWEEKNUM(Number)
tal är det interna datumtalet.
When entering dates as part of formulas, slashes or dashes used as date separators are interpreted as arithmetic operators. Therefore, dates entered in this format are not recognized as dates and result in erroneous calculations. To keep dates from being interpreted as parts of formulas use the DATE function, for example, DATE(1954;7;20), or place the date in quotation marks and use the ISO 8601 notation, for example, "1954-07-20". Avoid using locale dependent date formats such as "07/20/54", the calculation may produce errors if the document is loaded under different locale settings.
Unambiguous conversion is possible for ISO 8601 dates and times in their extended formats with separators. If a #VALUE! error occurs, then unselect Generate #VALUE! error in LibreOffice - PreferencesTools - Options - LibreOffice Calc - Formula, button Details... in section "Detailed Calculation Settings", Conversion from text to number list box.
=ISOWEEKNUM(DATE(1995;1;1)) returns 52. Week 1 starts on Monday, 1995-01-02.
=ISOWEEKNUM(DATE(1999;1;1)) returns 53. Week 1 starts on Monday, 1999-01-04.