Larry Shaw (1939 – 2017) the founder of Pi Day, at the Exploratorium in San Francisco.

Pi Day is an annual celebration of the mathematical constant
π (pi). Pi Day is observed on March 14 (the 3rd month) since
3, 1, and 4 are the first three significant figures of π, and it
was first celebrated in the United States. It was founded in
1988 by Larry Shaw a physicist at the San Francisco science
museum, the Exploratorium. Celebrations often involve eating
pie or holding pi recitation competitions. In 2009, the United
States House of Representatives supported the designation
of Pi Day.

Today is the day to go back in time. It’s National Retro Day!

It’s your day to look back – and think of easy times.

According to National Day Calendar, Hermelinda A. Aguilar
and Robert and Tina Duran founded National Retro Day to
take a look back at how life was before social media, the
internet, and smartphones became a necessity of our daily
lives.

National Freedom Day is an observance in the United States
that honors President Abraham Lincoln’s signing of a
resolution that proposed the 13th amendment of the
nation’s constitution on February 1, 1865.  

The Library of Congress credits Louis Lunch in New Haven
with inventing the hamburger in 1900. Cheese was first
added 24 years later in California^. Cheeseburgers have
been an iconic American food culture classic since the
1920s.

Original Louis’ Lunch proprietor Louis Lassen.

The earliest known Hot Dog Day was held in Alfred, New
York in 1972.