Calculate same day previous month DAX

[CliffordAP]

Hello everyone!

     I think my inquiry should be an easy one.

I want to find a way to compute a date based on the output of another date.

Say I have the following date,

     DATE(2021,01,16)
I want to simply adjust this date to the same day of the previous month such that it has the following output;

     DATE(2020,12,16)

Apparently PREVIOUSMONTH(DATE(2021,01,16)) does not work.

Any ideas?

[Anonymous]

Hello @CliffordAP 
You can use dateadd .
LastMonth = DATEADD('Table'[Date], -1, Month) 

[CliffordAP]

NVM!
I figured it out. There is a simple way to do this.

You can use the MONTH function to calculate the previous month of the output date, and subtract the number of months.

DATE(2021,MONTH(DATE(2021,01,16))-1,16)

output

DATE(2020,12,16). 🙂

[Anonymous]

@CliffordAP 

No, this is a very bad way to handle time calculations. Please read this and do not make mistakes others so easily do: Time Intelligence in Power BI Desktop - SQLBI

[AlexisOlson]

Looks good but watch out for the 31st. How do you want to handle those?