Difference between MAX and LASTDATE

[Reefman]

Hi,
I'm applying the following measures on a Calendar table with a [Date] column and a [Year] column:

[Row Count With MAX] = CALCULATE(
COUNTROWS(Calendar),
ALL(Calendar),
FILTER(
ALL(Calendar),
Calendar[Date]<=MAX(Calendar[Date])
)
)


[Row Count With LASTDATE] = CALCULATE(
COUNTROWS(Calendar),
ALL(Calendar),
FILTER(
ALL(Calendar),
Calendar[Date]<=LASTDATE(Calendar[Date])
)
)

If I use Calendar[Year] as a Row/Column label, [Row Count With MAX] returns the cumulative number of days at the end of each [Year] in my calendar ie, 365, 730, 1095, etc.. as I would expect, but the measure using LASTDATE always returns the total number of rows in my Calendar table.

Why the difference between these 2 functions?

(I know that I could re-write these measures differently, but I'd like to understand the different behavior in this context.)

Thanks!

Bruno

 

[Reefman]

Seems like LASTDATE changes the context in a way that I (and others!) didn't expect. I've found a post on Marco Russo site that explains what is happening: Usage of dates argument in a row context | SQLBI. Now I only need to understand it...