'On November 28th, 2012, Randall Munroe published an xkcd comic that was a calendar in which the size of each date was proportional to how often each date is referenced by its ordinal name (…) "In months other than September, the 11th is mentioned substantially less often than any other date. It's been that way since long before 9/11 and I have no idea why." After digging into the raw data, I believe I have figured out why.'

https://drhagen.com/blog/the-missing-11th-of-the-month/