Date Last Modified depth?

Hi guys,
I'm having a rule where any projects that I haven't touch in awhile gets archived in an old folder by checking the Date Last Modified on project folders. But I realised that the depth of the Date Last Modified is 1 level? The sub-folders/sub-files in my project which I edited recently isn't taken into consideration and the folder still gets moved to old even though I have just edited Project1>assets>scripts>something.css recently. Is there a way to check any file/folder within a folder if it has been modified recently?
I'm having a rule where any projects that I haven't touch in awhile gets archived in an old folder by checking the Date Last Modified on project folders. But I realised that the depth of the Date Last Modified is 1 level? The sub-folders/sub-files in my project which I edited recently isn't taken into consideration and the folder still gets moved to old even though I have just edited Project1>assets>scripts>something.css recently. Is there a way to check any file/folder within a folder if it has been modified recently?