On Kawara was a conceptual artist whose paintings, drawings, postcards, books, and recordings were driven by his preoccupation with time as a measurement of human existence. His early paintings were shown at the Tokyo Metropolitan Art Museum in 1953. His first trip outside Japan in 1959 initiated his lifelong penchant for traveling. On January 4, 1966, shortly after settling in New York, On Kawara began his famous “Today” series consisting of hundreds of “Date Paintings.” On a black or colored background he would paint only the date when the work was made, in white lettering, using the language of his location for that day. These visual records carry information about Kawara’s life and activities. One Million Years (1969), his multivolume work about the passage and marking of time, has been performed as a reading and also recorded. It lists each year, in the million-year periods, before and after the work’s conception. On Kawara participated in many biennials, including those in Tokyo (1970), Venice, and Kyoto (1976), and Documenta, Kassel (1972; 1982; 2002). The first major retrospective of his work was at the Solomon R. Guggenheim Museum in New York, in 2015.