Difference between rows based on ascending time

[Aleksandra_MLT]

Hi guys I want to calculate differences between volume per ID. I have no possibility to create Index in PQ.

So for example I want the yearliest value that day for that ID to be 0, then as per example :

7.17-7.16

7.16-7.15 and so on

[amitchandak]

@Aleksandra_MLT , Try

A new colum =

var _max = maxx(filter(Table, [Id] = earlier([ID]), [Timestamp at Datetime] <earlier([Timestamp at Datetime] )),[Timestamp at Datetime] )
return
if(isblank(_max), blank(), datediff(_max,[Timestamp at Datetime] , second))

or a new measure

measure =

var _max = maxx(filter(allselected(Table), [Id] = max([ID]), [Timestamp at Datetime] <max([Timestamp at Datetime] )),[Timestamp at Datetime] )
return
if(isblank(_max), blank(), datediff(_max,max([Timestamp at Datetime]) , second))

[Aleksandra_MLT]

Thank you, @amitchandak but getting errors:

also tried rermoving last part "