Time difference calculation

Hi Team,
I am currently in the process of writing a script which will take a filename in the format

SKADEV.0.db2.NODE0000.CATN0000.20080714231015.001

where the sixth string(with "." as the seperator) is the time stamp of the time of creation of the file.

now here is my issue .
I need to be able to calculate the age of this file based on the time stamp in the file name. I will be able to cut the timestamp out of the name using awk.
I can also convert this time stamp in DDMMYYYY format.
All i need is a way where i can calculate the age(i.e how many days old) of this file.
I am on Solaris 8 and using ksh.

The date command on my os is very limited so I do not have the luxuary of a lot of options.

Please assist.
Thanks in advance.

Some ideas here:

UNIX Scripting - Date comparison function

Thanks a lot for your help...I will try and post results!!!!!
Thanks again