Calculate number of days in a particular month/year between two dates

[chewbear]

Hi All

I am trying to identify a formula that will allow me to identify how many rental days occured between two dates in a particular month for a report I have to produce each month.

The report shows cars out on rent which in some case have been out for over 12 months and I need to be able to calculate how many rental days have occured for each booking in the relevant reporting month. I am currently doing this manually by manipulating data but want to try and find an automated way so I can write a macro!

I have attached an example of the type of data I am presented with:

Thanks in advance