This is definitely not personal data. The piece of information is not linked to an individual and cannot be used to identify an individual (not the same as a 'u

This is definitely not personal data. The piece of information is not linked to an individual and cannot be used to identify an individual (not the same as a 'user'), not least because it is not unique to each visitor: According to the article all first requests get the same 'last-modified' date, same for all second requests, etc. Still, this stores data in the browser in a way that might be deemed a technology similar to a cookie, and therefore this might still fall within the various cookie laws, but this is completely outside of personal data regs.