October 9 is National Nanotechnology day because 10/9 is loosely associated with the nanoscale length of 10^-9 meters. There are a large number of web resources and events commemorating the day. The ACS, for example, has a Nanotechnology webpage listing videos, podcasts, and references. A special webinar on 2D Materials and Beyond will be hosted on November 2 at 10 AM EDT.