There is nothing wrong with your computer. The Energy Saver control panel that comes installed on your computer contains a feature named "Document Auto-Save". The purpose of this feature is to automatically quit all open applications during an idle or scheduled shutdown, while saving changes to any open documents in each application.
The computer saves these documents in the folder named with the date and time. In your case, the computer appears to be shutting down while no applications are running, so no documents are saved.