Bizzard Behavior for YTD calcuation

[loti]

Using a simple model to illustrate the problem. The model consists of two tables

• a date table 
• a fact table

Date Table

In addition to the date, there is also a boolean column indicating whether that day is a weekend (I know the value is actual wrong, but it does affect the illustration)

Fact Table

Now if I define a YTD measure as 

YTD = CALCULATE(
	SUM('fact'[value]),
	DATESYTD(dim_date[Date])
)

I got the following incorrect results for YTD.

Given there are16 rows with that have a date that is label as a weekend as well as fact that all of them falls in the same year, I expect the `YTD` and `value`to be identical in the above.

Interesting enough, if I slightly change the DAX by using the `dim_date[Date].[Date]` instead of just `dim_date[Date]`, everything just works as expected.

YTD = CALCULATE(
	SUM('fact'[value]),
	DATESYTD(dim_date[Date].[Date])
)

I could figure out the logic behind all this. Can anyone help to explain what is actually going on here?

The example pbix file is here:

https://drive.google.com/open?id=1y3ndL7yDE7T4x7Z2bPhMsa-NHRgGzYj0

Thanks  

[Greg_Deckler]

See if my Time Intelligence the Hard Way provides a different way of accomplishing what you are going for.

https://community.powerbi.com/t5/Quick-Measures-Gallery/Time-Intelligence-quot-The-Hard-Way-quot-TIT...