Apple Event: May 7th at 7 am PT
Hi,
I am using the WEEKNUMBER formula in my spreadsheet to calculate the week number based on the date of a Monday.
This used to work correctly (in 2015) but with the new year, it goes wrong.
I tried both with the option 1 (Sunday) and option 2 (Monday) as first day of week.
Did I hit a bug?
Willem
I don't think there is a bug in the WEEKNUMBER function. However, I'm guessing you may be looking for the ISO week number. The WEEKNUMBER function does not return the ISO number. To get the ISO week number, if the date is in cell A2, then you can use this formula:
=INT((A2−DATE(YEAR(A2−WEEKDAY(A2−1)+4),1,3)+WEEKDAY(DATE(YEAR(A2−WEEKDAY(A2−1)+ 4 ),1,3))+5)/7)
If your date is in another cell just replace the A2 with that cell's address in the five places that A2 appears in the formula.
SG
I don't think there is a bug in the WEEKNUMBER function. However, I'm guessing you may be looking for the ISO week number. The WEEKNUMBER function does not return the ISO number. To get the ISO week number, if the date is in cell A2, then you can use this formula:
=INT((A2−DATE(YEAR(A2−WEEKDAY(A2−1)+4),1,3)+WEEKDAY(DATE(YEAR(A2−WEEKDAY(A2−1)+ 4 ),1,3))+5)/7)
If your date is in another cell just replace the A2 with that cell's address in the five places that A2 appears in the formula.
SG
Using WEEKNUMBER() in Numbers
