It never ends that our management wants to implement some kind of new function...

We need to be able to scan a drive for files that have not been accessed for the past 6 months. If not, then zip the file and remove the file just zipped. Zipping the file seems easy enough to do but what we are having a problem with is the best way to find the files last accessed.
We have backups running everyday. The files are touched by the backup process so when we do a scan for files last accessed in the past 1 day, all files show up. We don't think scanning for a last modified date will work because many of us use reference files for information. We seldom change the content so it is possible to have a file that is used everyday but has not been modified for a long time and would then cause the file to be zipped if we queried on the last modified date.
Does anyone have any suggestion how to search for files last accessed by datetime? I am not sure if it is possible but if we could search for a file last accessed and exclude the "user account" from the backup, we could get the info.
Is there any way to do an object call against the files looking for the username that accessed the file?

thanks for any suggestions...
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John
LM Contractor
One of the 2 dads