Difference between two dates.

Hi all.
My question may seems to be similar to one that already been here. But i need a little other solution.
I have two dates in format dd/mm/yyyy. I need to find number of days between them. I need to do it in bash script.
I am running on Solaris machine and have cutted 'date' command version - without -d option.
I have awk, and nawk installed, no gawk. And i have perl. But i have no any experience in all those tools and have no time to learn now.
So anybody can post a solution with awk or perl, please. Number of days between to in given format.

A link with examples regarding Date Arithmetic:

http://www.unix.com/answers-frequently-asked-questions/13785-yesterdays-date-date-arithmetic.html

Regards