It is Tau day today because it's the 28/6 (for u.s. it is 6/28) Taus first three digits are 6.28
What is Tau? It is a replacement of pi (Pi X 2 = Tau). For example: 2 pi X radius X circumference where Tau X radius = circumference. I really think we should have been using tau all along since it makes a lot more sense. (But we all know and love pi because it is pi(pie))
but who knows
http://www.mathgoodies.com/images/Tau_blog.png for president 2016.