Date-Time Stamp of Knime Workflow Folder

Why does the date-time stamp on a Knime workflow folder get set to today's date when I open the workflow and close it without any changes / saves?  This makes it hard to determine when the flow was last edited.  Right clicking on workflow and chosing properties gives the last edit date as today as well even though I did not make any changes. It doesn't seem like it should work this way.

Mark Andrews