A Day Twice As Nice

There's Pi Day, of course, on March 14, or 3.14. It's notable date, celebrating as it does a most reputable and essential cipher. Since 2010, though, it's had a competitor for your devotion ~ Tau Day, or 6.28, aka 2 Pi Day (http://somanyinterestingthings.blogspot.com/2014/06/the-joy-of-628.html). What argument could possibly be made for Tau Day, you might ask. Well, allow educator and physicist Michael Hartl to elucidate: "Since the circle constant is important, it’s important to get it right," he writes in his Tau Manifesto, "and we have seen in this manifesto that the right number is τ. Although π is of great historical importance, the mathematical significance of π is that it is one-half τ." And, yes, the day is gaining its adherents and, consequently, recommended ways of celebrating in style: http://www.scientificcomputing.com/blogs/2015/06/are-you-tau-ist-pi-day-under-attack