Google Drive lets you share files easily enough, but you can't set an expiration date if you want to block access after a certain amount of time. Tech blog Digital Inspiration shows how you can add an automatic expiration date to folder with a simple Google Script.
To set up expiration dates, you need to make a copy of a Google Script, add the URL of your Google Drive folder (it doesn't work with individual files), and then set the expiration date. Run the script and your folder's sharing privileges will automatically expire at the specified time. Head over to Digital Inspiration for the full guide to doing this yourself.
Set Auto-Expiry Dates for Shared Folders in Google Drive [Digital Inspiration]