You may get more help by posting all example data in the form of a data step. If you don't know how to convert your SAS data into data step code Instructions here: https://communities.sas.com/t5/SAS-Communities-Library/How-to-create-a-data-step-version-of-your-data-AKA-generate/ta-p/258712 will show how to turn an existing SAS data set into data step code that can be pasted into a forum code box using the {i} icon or attached as text to show exactly what you have and that we can test code against. One reason the data step is good idea is then we do not have to guess which of your variables may be numeric or character and whether any date variables are actually SAS date values or not (there are a large number of things that you can do with SAS date valued variables that are impractical directly with other forms of dates).   As a minimum you will have to explain such things as how "amount" in your example output is generated from the amounts in the input data.   Also how does the MonthEndDate apply to the process. For instance you have a value of MonthEndDate of 30/3/2017 for AccountId 111 CountryCode SG ProductCode LON for the transactiondate of 20/10/2016. Since your example output only shows 31/3/2017 for the MonthEndDate does that mean this particular record is excluded? Or is there some additional combination rule you haven't describe. ... View more