Compare each day’s index with the previous day index

[Rolosig]

Hi,

I'm trying to compare each day’s index with the previous day index. I'm using the previous day function but the problem with that is that it only goes back one day but not on the last "index day", so my problem is the holidays and the weekends. This is the measure that I used Previous day = CALCULATE(sum(table[Index]), PREVIOUSDAY(table[Date])).

Can you please help me either make a measure or a collum that gives me value for the last index day so I can calculate the difference between each day. I think the picture of the matrix below explains it better:

 

All the best,
Robert 

[Rolosig]

@Greg_Deckler  Thank you it worked!

[Greg_Deckler · Accepted solution]

@Rolosig See my article on Mean Time Between Failure (MTBF) which uses EARLIER: http://community.powerbi.com/t5/Community-Blog/Mean-Time-Between-Failure-MTBF-and-Power-BI/ba-p/3395....
The basic pattern is:
Column = 
  VAR __Current = [Value]
  VAR __PreviousDate = MAXX(FILTER('Table','Table'[Date] < EARLIER('Table'[Date])),[Date])
  VAR __Previous = MAXX(FILTER('Table',[Date]=__PreviousDate),[Value])
RETURN
  __Current - __Previous