Massachusetts Institute of Technology has often mailed its application decision letters to prospective students for delivery on Pi Day. Starting in 2012, MIT has announced it will post those decisions (privately) online on Pi Day at exactly 6:28 pm, which they have called “Tau Time”, to honor the rival numbers pi and tau equally. In 2015, the regular decisions were put online at 9:26 am, following that year’s “pi minute”. June 28 is “Two Pi Day”, also known as “Tau Day”. 2π, also known by the Greek letter tau (τ) is a common multiple in mathematical formulae. Some have argued that τ is the more fundamental constant, and that Tau Day should be celebrated instead. Celebrations of this date jokingly suggest eating “twice the pie”.