I have attempted to do what was suggested - looking inside the content.opf file
... but in all likelihood, did not go about it the correct file. I opened the file in dreamweaver and found the line:
<dc:date>*September*</dc:date>
And changed it as suggested. However, when you resave the file with dreamweaver it adds the suffix xhtml to .opf, so it reads: opf.xhtml
So I then renamed the file by omitting the .html
I then rezipped the contents and changed the file type from .zip to .epub
When I did this method and redid the validator, I now have this error:
