Fiscal Date difference Calculation

[jeeva]

Hi Techies,

I have a requirement to calculate the difference for fiscal dates. means, i have a list report. it contains all dates with the measures. so i need to find the difference of the fiscal dates as below

date              measure         fiscal_percentage
---------------------------------------------------------------
12-07-14        1500           
26-07-14        5000           
11-07-15        500              1000 (first date - third date)
25-07-15        3000            2000 (second date - fourth date)


Please suggest me.

Thanks in advance