New year problem with Week #

[Emil_Lilja]

So i have a simple formula for calculating the week number to make grouping the records easier. When 2020 came around it got grouped with 2019 so i switched it to a DATETIME_FORMAT to show both year and week. ezpz should be solved.
But noticed that for some reason the 27th-31th of December in 2020 is calculated as weeknum 1 of 2020? Also tried setting the timezone but no luck there. The days of the week are also shifted. At least in Sweden (and i would guess most places?) Week 1 of 2020 starts 30th Dec and ends 5th Jan. Any takes on why Airtable calculates it like this?

[Christopher_Bre]

This formula should solve your problem

IF(AND(DATETIME_FORMAT(date,“YYYY - Wo”),DATETIME_FORMAT(date,‘M’)=12),CONCATENATE(DATETIME_FORMAT(date,“YYYY”),"- 52"),DATETIME_FORMAT(date,“YYYY - W”))

[Emil_Lilja]

Smooth solution man!

Although for some reason this created another problem that i also can’t figure out, all of Dec 2019 gets grouped to week 52?
Better than before but still

[Christopher_Bre]

IF(AND(DATETIME_FORMAT(date,“W”)=1,DATETIME_FORMAT(date,‘M’)=12),CONCATENATE(DATETIME_FORMAT(date,“YYYY”),"- 52"),DATETIME_FORMAT(date,“YYYY - W”))

I messed up on the first part of the formula. This should fix it for you.

[Emil_Lilja]

My man!

Creative solution