SQL & PL/SQL :: Complex Days Computation / Multiple Number Of Same Transaction Dates

The data in one of the temporary table has been compiled as below. Number of Days elapsed between two transaction dates is required to be computed and multiplied with the balance. There can be multiple number of same transaction dates. When previous date and the current transaction dates are same the resulting number of day difference should be 0. But when they are different the difference between them is to be computed. On the last day of the Financial Year i.e. '31/03' of any year the difference day should be shown as 1 so as to make 365 or 366 days in a year. Simply deducting d1 from d2 on 31st will not be suffice as the difference is one day less.

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Transaction Narration DebitCreditBalanceNo of DaysProduct
DateDifference
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01/04/2009Opening Balance 45020450277346654
17/06/2009ByAmt5044521253424
29/06/2009By Amt1004352156678912
02/12/2009By Amt424310119476000
[code]....

improve the above code and get the desired output result.