Last Modified question..

I have a problem... I want to check the last modified time that a file was changed/updated. Actually, it's an employee database that I'm working on and I thought about just checking the last modified date on the file that the information was stored on. However, I get a permission denied error and I don't want to change the permissions of the file. Is there an easy way to check to see when the last time anyone logged in and updated their 'employee' information? Thanks, jay