Is it possible: Automator workflow for date based file import?
This will be difficult with Automator but it is possible. You will need to augment your Automator workflow with Run Script steps involving some other scripting language. That language can be shell script, AppleScript, or another command line capable tool such as perl.

Alternatively, you may find a third party tool like Hazel is able to help:


  Hazel watches whatever folders you tell it to, automatically organizing your files according to the rules you create. It features a rule interface similar to that of Apple Mail so you should feel right at home.