DAX to count rows where date is null or in last 2 months

[lilych]

Hello,

I'm struggling with DAX. I am trying to create a calculated column that count rows in a table where the date is either blank OR within the past 2 calendar months based on today's date. How would I write out the DAX for this? The main part I am struggling with is if the date is within the current month or previous month.

ID	Date	Cal. Column
1		1
2	4/15/2021
3	3/20/2020
4	5/3/2021	1
5	6/2/2021	1
6	4/28/2021

Thank you -

[ChrisMendoza]

@lilych - Try:

Column = 
IF(
    MONTH(TableName[Date]) > (MONTH(TODAY()) - 2)
    || ISBLANK(TableName[Date]),
    1,
    BLANK()
)

[lilych]

Thanks @ChrisMendoza! It works for dates in this year where it excludes rows from Jan-April 2021, however in my file, it seems to be including rows where the date is in 2020. How can I exclude that? 

[ChrisMendoza · Accepted solution]

@lilych - Ah! I see what you mean. You can do as an IF:

Column =
IF (
    AND (
        MONTH ( TableName[Date] )
            > ( MONTH ( TODAY () ) - 2 ),
        YEAR ( TableName[Date] ) = YEAR ( TODAY () )
    )
        || ISBLANK ( TableName[Date] ),
    1,
    BLANK ()
)

or you can do as SWITCH:

SWITCHColumn = 
SWITCH (
    TRUE (),
    ISBLANK ( TableName[Date] ), 1,
    AND (
        MONTH ( TableName[Date] )
            > ( MONTH ( TODAY () ) - 2 ),
        YEAR ( TableName[Date] ) = YEAR ( TODAY () )
    ), 1,
    BLANK ()
)

[lilych]

Thank you @ChrisMendoza, that worked!