Changing creation or modification date with Automator

Question

Three computers access iTunes in my apartment. The files are located on a drive connect to an airport extreme base station. Each computer needs to import music and have physical access to it for iPods and playlist creation. Since iTunes does not automatically check for new files I am in the process of building an Automator script to fix the problem.
I have created an Automator action that allows the user to control-click a folder with audio files in it and have Automator manually change the file name, then import the files into iTunes. My hope was that this would change each files modification date so that, at a later time, another Automator action could search the network drive for newly added media via the modification date. My problem is that simply changing the name does not change the modification date. Even creating an archive and unzipping it before importing does not change the date.
What action can I do with Automator that will change the modification date on those files so that I can search for them later? I know I can add the date to the file name but I don't want a user to have to guess which dates files were added (i.e. I'd have to tell Automator "look for this specific date in the file name' which is obviously unhelpful if I don't know the specific date).
Long story short, how can I change either dates with Automator?

Answer 1

Create a column with the following.
TIMESTAMPDIFF( SQL_TSI_day, Opportunity."Created Date" , CURRENT_TIMESTAMP )
add a filter on this column, for example, <=90.
the SQL_TSI_month does not return accurate number of months.
Cheers!
Shilei