Week number

[Anonymous]

Hi all,

How can I achieve the following week number results?:

Day	Date	ISO8601	Special
Thursday	31.12.2020	53	53
Friday	01.01.2021	53	1
Saturday	02.01.2021	53	1
Sunday	03.01.2021	53	1
Monday	04.01.2021	1	1
Tuesday	05.01.2021	1	1
Wednesday	06.01.2021	1	1
Thursday	07.01.2021	1	1
Friday	08.01.2021	1	1
Saturday	09.01.2021	1	1
Sunday	10.01.2021	1	1
Monday	11.01.2021	2	2

Looking forward to your answers.

Thanks.

[v-yingjl]

Hi @Anonymous ,

Based on your description, seems like you want to define 10 days as a week for each year, you can create a calculated column like this:

Special =
ROUNDUP (
    DIVIDE (
        DATEDIFF ( STARTOFYEAR ( 'Table'[Date].[Date] ), 'Table'[Date], DAY ) + 1,
        10
    ),
    0
)

Attached a sample file in the below, hopes to help you.

Best Regards,
Community Support Team _ Yingjie Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[Anonymous]

Hello,

Thank you for that.

How can I get the week numbers to calculate based on the ISO8601?:

Day	Date	Week Number ISO8601
Thursday	31.12.2020	53
Friday	01.01.2021	53
Saturday	02.01.2021	53
Sunday	03.01.2021	53
Monday	04.01.2021	1
Tuesday	05.01.2021	1
Wednesday	06.01.2021	1
Thursday	07.01.2021	1
Friday	08.01.2021	1
Saturday	09.01.2021	1
Sunday	10.01.2021	1
Monday	11.01.2021	2

Looking forward to hearing back from you.

Best regards.

[v-yingjl · Accepted solution]

Hi @Anonymous ,

You can create the calculated column like this:

ISO8601 = WEEKNUM('Table'[Date],21)

Please refer the [ISO] column in my sample file from the previous post.

Best Regards,
Community Support Team _ Yingjie Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[amitchandak]

@Anonymous , there is an issue reported for that.

https://community.powerbi.com/t5/Issues/DAX-WEEKNUM-gives-incorrect-values-since-jan-1st-2021/idi-p/1583824

For 2021, try like new week column like

Week Number =

if(Year([date] = 2021 && WEEKNUM([Date],2) >=2, WEEKNUM([Date],2) -1,WEEKNUM([Date],2))

[Anonymous]

Hi Amit,

And how would it work the previous and following years?

Many thanks.

[amitchandak]

@Anonymous , You have to tell the logic, I can give that.

Also, vote for the issue.