Running Total without Max(Date)

Hello,

I did try something out with the running total. Normally that is the standard running total for one sales and one date column from a mastercalendar:

Measure =

calculate(sum(Sales[Sales]),

Filter(

ALL('Calendar'[Date]),

'Calendar'[Date]<= MAX('Calendar'[Date])

))

 

My question is why 'Calendar'[Date] needs to be aggregated with Max function? 

 

Measure 1=

calculate(sum(Sales[Sales]),

Filter(

ALL('Calendar'[Date]),

'Calendar'[Date]<=('Calendar'[Date])

))

 

For example if the computing of the row 31-01.2021 happens, shouldnt't that happen in the background: 

'Calendar'[31-01.2021]<=('Calendar'[31-01.2021])

 

Shouldn't here be all the dates smaller or equal 31-01-2021 be included?

Instead for Measure 1 I always get only the total sum in every row. 

 

Thank you very much in advance.

Best regards.