Weeknumber when week starts on Sunday

Hi Rapaille,

to get a week number but starting from sunday, you can try this formula.

=CONCATENATE(TEXT(IF(INT((Productiedatum-DATE(YEAR(Productiedatum),1,1)+(TEXT(WEEKDAY(DATE(YEAR(Productiedatum),1,1),1),"d")))/7)=0,52,INT((Productiedatum-DATE(YEAR(Productiedatum),1,1)+(TEXT(WEEKDAY(DATE(YEAR(Productiedatum),1,1),1),"d")))/7));"0"))

Here's what the formula does:

- It takes your date, which is in the "Productiedatum" column.
- It figures out how many days have passed since the beginning of the year (January 1st).
-  Then, it checks if this number is zero (meaning the date is still in the previous year's week 52). If it's zero, it assigns the week number as 52.
- If it's not zero, it calculates the week number based on the number of days passed and divides it by 7 to get the week number.