Dictionary

Pi Day en · PROPN

Pronunciation

• /ˈpaɪ deɪ/ (General-American, Received-Pronunciation)
• (Australia) audio

Etymology

pi + day, from the date March 14th in the month/day format (that is, 3/14), 3, 1 and 4 being the first three significant digits of the mathematical constant π.

Meanings

1. March 14th, an annual celebration of the mathematical constant π (pi).
   • March 14, or 3/14, is recognized by math geeks as Pi day. That happens every year. But as UBS’s Art Cashin notes, next year’s Pi day will be a once-in-a-century Pi day. “At 9:26:53 a.m., they can write 3/14/15; 9:26:53, which you should also recall are the first ten digits of Pi in perfect order,” said Cashin. 2015 March 14, Sam Ro, “March 14, 2015 will be a once-in-a-century thrill for math geeks”, in Business Insider, archived from the original on 04 Mar 2016:
   • Did you know that March 14 is Pi Day (no, π is not misspelled). Pi Day is celebrated on 3/14 or 3.14! To commemorate this remarkable ratio, we have a few circular activities. The first is the Pizza Survey. What are the students' favorite toppings on pizza? What do you like best? 1997, Louise Bock, Susan Guengerich, Hope Martin, “March Celebrations”, in Multicultural Math Fun: Holidays around the Year, Portland, Me.: J. Weston Walch Publisher, →ISBN, page 83:
   • Of all known mathematical constants, however, pi continues to attract the most attention. […] The Exploratorium in San Francisco continues to celebrate Pi Day on March 14 each year, starting at 1:59 pm. 2002, Ivan Peterson, “A Passion for Pi”, in Mathematical Treks: From Surreal Numbers to Magic Circles (Spectrum Series; a Science News Book), [Washington, D.C.]: Mathematical Association of America, →ISBN, page 17:
   • As Quakers, we do not as a matter of religion celebrate any holidays (more accurately, all days are to be considered holidays because they have equal potential for revealing the Divine to us), but as a cultural matter we celebrate all kinds: Hindu, Christian, Jewish, ethnic, birthdays of famous composers, artists, writers, and scientists, π Day (March 14th – we bake several pies and divide them into fractions before eating), even some we just make up ourselves. 1999, David H. Albert, “Exits and Entrances”, in And the Skylark Sings with Me: Adventures in Homeschooling and Community-based Education, Gabriola Island, B.C.: New Society Publishers in cooperation with Holt Associates/Growing Without Schooling, →ISBN, page 128:
   • Whereas Pi can be approximated as 3.14, and thus March 14, 2009, is an appropriate day for "National Pi Day": Now, therefore, be it / Resolved, That the [United States] House of Representatives— / (1) supports the designation of a "Pi Day" and its celebration around the world; […] 2009 March 12, H. Res. 224 Supporting the Designation of Pi Day, and for Other Purposes, [Washington, D.C.]: United States Government Publishing Office, archived from the original on 28 Dec 2016, page 2:
   • Likewise, March 14 in North America has been π Day, since in the USA the month is written before the day ('314'). In schools throughout North America, it has become a reason for mathematical projects, especially focussing on π. 2012 June 19, Jonathan M[ichael] Borwein, “The Life of Pi: From Archimedes to Eniac and Beyond”, in David H[arold] Bailey, Jonathan M. Borwein, Pi: The Next Generation: A Sourcebook on the Recent History of Pi and Its Computation, Switzerland: Springer Nature, published 2016, →DOI, →ISBN, page 446:
   • Pi lovers like to celebrate Pi Day every year. In the US, they write the date with the month first, then the day and year. So in 2015, 14th March was 3 14 15, the first five digits of π. So that was a really special Pi Day when, of course, they sang their special song, Pi, Pi, Mathematical Pi, to the tune of that great song everyone danced to in the 1970s, 'Bye-bye, Miss American Pie' by Don McLean. 2016, Liz Strachan, “A Little More Pi”, in Easy as Pi: Maths Made Simple, London: Robinson, →ISBN:

Forms

Translations (51)

cmn 圓周率日 /圆周率日 (March 14th, an annual celebration of the mathematical constant π (pi)) · mk Ден на бројот пи (March 14th, an annual celebration of the mathematical constant π (pi)) · ka პის დღე (March 14th, an annual celebration of the mathematical constant π (pi)) · pl Dzień Liczby Pi (March 14th, an annual celebration of the mathematical constant π (pi)) · it Giorno del pi greco (March 14th, an annual celebration of the mathematical constant π (pi)) · uk День пі (March 14th, an annual celebration of the mathematical constant π (pi)) · id Hari Pi (March 14th, an annual celebration of the mathematical constant π (pi)) · th วันพาย (March 14th, an annual celebration of the mathematical constant π (pi)) · as পাই দিৱস (March 14th, an annual celebration of the mathematical constant π (pi)) · eo Pi-tago (March 14th, an annual celebration of the mathematical constant π (pi)) · ru День числа пи (March 14th, an annual celebration of the mathematical constant π (pi)) · vi Ngày số pi (March 14th, an annual celebration of the mathematical constant π (pi)) · cv Пи хисепӗн кунӗ (March 14th, an annual celebration of the mathematical constant π (pi)) · es Día de Pi (March 14th, an annual celebration of the mathematical constant π (pi)) · ca Dia Pi (March 14th, an annual celebration of the mathematical constant π (pi)) · fa روز پی (March 14th, an annual celebration of the mathematical constant π (pi)) · pt Dia do Pi (March 14th, an annual celebration of the mathematical constant π (pi)) · fi piin päivä (March 14th, an annual celebration of the mathematical constant π (pi)) · nl pi-dag (March 14th, an annual celebration of the mathematical constant π (pi)) · tr Pi Günü (March 14th, an annual celebration of the mathematical constant π (pi)) · ml പൈ ദിനം (March 14th, an annual celebration of the mathematical constant π (pi)) · bg Денят Пи (March 14th, an annual celebration of the mathematical constant π (pi)) · nl pi-benaderingsdag (March 14th, an annual celebration of the mathematical constant π (pi)) · sw Siku ya Pi (March 14th, an annual celebration of the mathematical constant π (pi)) · fr journée de pi (March 14th, an annual celebration of the mathematical constant π (pi)) · ckb ڕۆژی پای (March 14th, an annual celebration of the mathematical constant π (pi)) · de Pi-Tag (March 14th, an annual celebration of the mathematical constant π (pi)) · da Pi-dag (March 14th, an annual celebration of the mathematical constant π (pi)) · sh Dan broja pi (March 14th, an annual celebration of the mathematical constant π (pi)) · is Nálgunardagur π (March 14th, an annual celebration of the mathematical constant π (pi)) · ja 円周率の日 (March 14th, an annual celebration of the mathematical constant π (pi)) · yue 圓周率日 /圆周率日 (March 14th, an annual celebration of the mathematical constant π (pi)) · et Pii päev (March 14th, an annual celebration of the mathematical constant π (pi)) · ne पाई दिवस (March 14th, an annual celebration of the mathematical constant π (pi)) · hy Պի թվի օր (March 14th, an annual celebration of the mathematical constant π (pi)) · ro Ziua pi (March 14th, an annual celebration of the mathematical constant π (pi)) · sl Dan pi (March 14th, an annual celebration of the mathematical constant π (pi)) · bn পাই দিবস (March 14th, an annual celebration of the mathematical constant π (pi)) · hu nemzetközi π-nap (March 14th, an annual celebration of the mathematical constant π (pi)) · sk Deň pí (March 14th, an annual celebration of the mathematical constant π (pi)) · lt Pi diena (March 14th, an annual celebration of the mathematical constant π (pi)) · ta பை நாள் (March 14th, an annual celebration of the mathematical constant π (pi)) · nn Pi-dagen (March 14th, an annual celebration of the mathematical constant π (pi)) · cs Den pí (March 14th, an annual celebration of the mathematical constant π (pi)) · or ପାଇ ଦିବସ (March 14th, an annual celebration of the mathematical constant π (pi)) · sv Pi-dagen (March 14th, an annual celebration of the mathematical constant π (pi)) · ar يوم ط (March 14th, an annual celebration of the mathematical constant π (pi)) · si පයි දිනය (March 14th, an annual celebration of the mathematical constant π (pi)) · ko 파이의 날 (March 14th, an annual celebration of the mathematical constant π (pi)) · is π dagur (March 14th, an annual celebration of the mathematical constant π (pi)) · he יום פאי (March 14th, an annual celebration of the mathematical constant π (pi))

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