calculate date before

[AnaIsa]

Hi, 

How I can calculate a previous date  since a column with a data time received. Example: I have a column with this date:

I want to calculate a previous date, it would be 31/03/24

thank you

[v-yaningy-msft · Accepted solution]

Hi, @AnaIsa 

Thanks for @lbendlin reply. This is an additional step to his response, if you are confused how to proceed, you can refer to the following methods.

1. Power Query

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjDRNzDUNzIwMlGKjQUA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t]),
    #"ChangedType" = Table.TransformColumnTypes(Source,{{"Date", type date}}),
    AddedCustom = Table.AddColumn(ChangedType, "Previous Day", each Date.AddDays([Date], -1), type date)
in
    AddedCustom

2. Power BI Desktop

Previous Day 2 = 
VAR _previousDate = CALCULATE(SELECTEDVALUE('Table'[Date]) - 1)
RETURN
_previousDate

Or use Dateadd function directly.
DATEADD - DAX Guide

Best Regards,
Yang
Community Support Team

If there is any post helps, then please consider Accept it as the solution  to help the other members find it more quickly.
If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

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[AnaIsa]

I would like to see the sales value for previous month at product detail, I only see it in a general table like this:

but if I want to see by detail, If I select a month I see the same amount for AC and AC-1, the formula used for AC-1 is: 

Transit AC-1 = CALCULATE([Total Transit],(DATEADD('Date'[Date],-1,MONTH)))

could you help me please ?

[lbendlin]

In Power Query you subtract #duration(1,0,0,0) . In DAX you subtract 1.