Holidays. Paydays. Your birthday. They're all important in their own special ways. But which day of the year is the most important? This handy calendar visualization from xkcd reveals all.
The rankings are based on Google NGrams searches, which tell you how often given words or phrases are used in English-language books over a set period of time. In this case, since 2000. The big winner—if you can call it that—here is, understandably, Sept. 11th, and the first days of months are surprisingly popular as well.
As for the rest of the year, well, it's fun to search around for yourself. And I'll also leave it to you to figure out why July 11th gets no love. [xkcd]