Income for overlapping months to be split daily...

Ok....I extract a report from the system as per below.

Opening Date----- Closed Date----- Days ----- Revenue
01-09-2013 ----- 05-09-2013 ----- 5----- 83.02
15-10-2013 ----- 27-10-2013 ----- 13 -----305.09
15-10-2013 ----- 22-10-2013 ----- 8----- 85.38

01-10-2013 ----- 10-11-2013 ----- 41----- 619.70
28-10-2013 ----- 10-11-2013 ----- 14 -----350.00

The revenue is divided equally on the days. (ie for the first line 5 days = 83.02; 1 day = 16.604)
For the first three lines of data; its fine; as it is within the same month; IE the revenue of 83.02 is for September and 305.09+85.38 is for October.

However, line 4 and 5 are split between different months.

01-10-2013 ----- 10-11-2013 ----- 41----- 619.70 [[[[ 31 days should go under October and 10 days goes under November)
28-10-2013 ----- 10-11-2013 ----- 14 -----350.00 [[[[ 4 days should go under October and 10 days goes under November)

Any idea what formulas I could use? I am attaching the report with what I tried to do... but as i said, for different months i have failed to come up with a formula.

Thanks
Sam