How to compute Date from Input Parameter?

HI ppgandhi111,

You can use Date.AddMonths function to go back 3 months from the StartDate Parameter.

Could you please try to build similar Power Query in Advanced editor in Edit Query.

let
    sDate=DateTime.ToText(Date.AddMonths(DateTime.FromText(StartDate),-3),"MM/dd/yyyy"), 
    eDate=EndDate,
    Source = Sql.Database("SERVERNAME", "DATABASE_NAME", [Query="select * from customers a where a.receiveddt between '" & sDate & "' and '" & eDate & "'"]),
    dbo_customers = Source{[Schema="dbo",Item="customers"]}[Data]
in
    dbo_customers

Please change "SERVERNAME" & "DATABASE_NAME" as per your instance configuration.

Below line in above code goes back 3 months from the given date parameter (StartDate).

sDate=DateTime.ToText(Date.AddMonths(DateTime.FromText(StartDate),-3),"MM/dd/yyyy")

Please let me know if this helps.

Thanks,

Rahul