Previous Year measure - Function Dateadd expects a Contiguous Selection

Hi, 
one of ways to achieve this is to have a proper calendar table, and this contains continuous date column.

I tried to create one more calendar table in the sample pbix file, and please check the below picture and the attached pbix file.
The data model is not well optimized, but I tried not to remove anything from your model, and add one more calendar table.

calendar_new = 
VAR _newdate =
    ADDCOLUMNS (
        CALENDAR ( DATE ( 2021, 1, 1 ), DATE ( 2025, 12, 31 ) ),
        "@startofmonth", EOMONTH ( [Date], -1 ) + 1
    )
VAR _generate =
    GENERATE (
        _newdate,
        FILTER (
            'Sample Calendar',
            'Sample Calendar'[Start of Month] = [@startofmonth]
        )
    )
RETURN
    _generate

Hi TotalAnonymous,
Thank you for your thoughtful follow-up and I'm glad to hear the original solution worked for you.

Yes, it’s common to work with fact tables that aren’t at daily granularity. In such cases, here are some best practices:

• Even if your fact has only Week Number or Start of Month, link it to a proper date table to enable time intelligence functions like DATEADD and TOTALYTD.
• Map fact data to the calendar using Start of Month, Start of Week, or a Year-Month key.
• Use inactive relationships and USERELATIONSHIP() when needed to keep your model clean.

The key is making sure your calendar table is continuous and your joins to it are clean and consistent.

If this information is helpful, please “Accept as solution” and give a "kudos" to assist other community members in resolving similar issues more efficiently.
Thank you.