Question: What is the birthdate of this American dancer and choreographer of modern dance, who helped found the Joseph Campbell Foundation with Robert Walter?

Context paragraphs:
Joseph Campbell Foundation: The Joseph Campbell Foundation is a US not-for-profit organization dedicated to preserve, protect and perpetuate the work of influential American mythologist Joseph Campbell (1904–1987).  It fosters academic and popular discussion in the fields of comparative mythology and religion, psychology and culture through its publishing program, events, local groups (Mythological RoundTable groups) and its internet presence.

Ze'eva Cohen: Ze'eva Cohen is a dancer, modern dance choreographer, and dance professor emeritus at Princeton University.  Cohen grew up in Tel Aviv, Israel, the daughter of Yemeni immigrants.  She traveled to New York City from Israel in 1963 to study at the Juilliard School and perform with the Anna Sokolow Dance Company.  She danced with the company for ten years.  Cohen was also a founding member of Dance Theater Workshop, where she worked as a choreographer and dancer from the mid-sixties to the early seventies.  She has created a body of choreographic work which links her background in American modern dance with her Yemenite Jewish heritage.

Peter Randazzo: Peter Randazzo (born January 2, 1943, in Brooklyn) is an American dancer and choreographer known for his contributions to modern dance.  From 1962–1968 he was a principal dancer with the Martha Graham Dance Company.  In 1968 he co-founded the Toronto Dance Theatre (TDT) and its associated school, The School of Toronto Dance Theatre, with fellow Martha Graham disciples Patricia Beatty and David Earle.  A prolific choreographer, the TDT has featured his works in performances internationally for more than 40 years.

Lila York: Lila York (born 29 November 1948) is an American dancer and choreographer based in New York City.  She studied English Literature at Skidmore College before studying ballet and modern dance at the Martha Graham Center of Contemporary Dance and with Paul Sanasardo.  York joined the Paul Taylor Dance Company in 1973 where she danced for more than a decade.  After leaving the company, she left the "very heart of American modern dance" to become one of "ballet's most sought-after choreographers", working with many of the world's foremost ballet companies.

Robert Walter (editor): Robert Walter is an editor and an executive with several not-for-profit organizations.  Most notably, he is the executive director and board president of the Joseph Campbell Foundation (JCF), an organization that he helped found in 1990 with choreographer Jean Erdman, Joseph Campbell's widow.

Jean Erdman: Jean Erdman (born February 20, 1916) is an American dancer and choreographer of modern dance as well as an avant-garde theater director.

Barton Mumaw: Barton Mumaw (20 August 1912 – 21 June 2001) was an American dancer and choreographer who performed in modern dance concerts and musical theater productions.  He was the muse of Ted Shawn, pioneer of modern dance.

Contemporary dance in Japan: Western schools covered classical ballet, jazz-dance, and modern dance and influenced the butoh avant-garde dance movement.  Ballet was said to have replaced traditional Japanese arts, such as flower arrangement and the tea ceremony, in the hearts of young girls.  Prima ballerina Morishita Yoko sat on the jury for the Prix de Lausanne Ballet Competition in 1989, held for the first time in Tokyo, marking the arrival of Japanese classical ballet in the international community.  Horiuchi Gen, a 1980 Prix de Lausanne winner, became a major soloist with the New York City Ballet, and Japanese performers noted for their superb technique were members of many major international companies.  Modern dance was performed early after World War II and was later taught by such famous dancers as Eguchi Takaya.  The Tokyo Modern Dance School and the Ozawa Hisako Modern Dance Company also promoted avant-garde modern dance.  A wide experimental range within modern dance occurred from which choreographer Teshigawara Saburo skillfully drew to create multifaceted works for his KARAS Company.

Graham technique: Graham technique is a modern dance movement style and pedagogy created by American dancer and choreographer Martha Graham (1894–1991).  Graham technique has been called the "cornerstone" of American modern dance, and has been taught worldwide.  It is widely regarded as the first codified modern dance technique, and strongly influenced the later techniques of Merce Cunningham, Lester Horton, and Paul Taylor.

Stephen Larsen: H. Stephen Larsen is a psychologist and author who, with his wife Robin Larsen, was on the founding board of advisors of the Joseph Campbell Foundation, and also founded the Center for Symbolic Studies, to carry on with the work of Joseph Campbell.  He is best known for his work in mythology, and for being a pioneer in the field of neurofeedback.

Supporting paragraphs: Robert Walter (editor) Jean Erdman
Answer: February 20, 1916