On Kawara's "Date Paintings," such as 19 JUL. 68, are examples of Conceptual art, an aesthetic philosophy that values a work's motivating ideas at least as much as the work itself. In these paintings, the artist employs a uniform format of small stretched canvases, which he paints evenly in gray, blue, black, or red acrylic on all five visible planes. In the center of the front plane On Kawara paints the date of the work in white. He thus eliminates questions of composition in favor of an uninflected declaration of chronology.
The paintings can be seen as diaristic, although only in a limited way. They offer few clues about the artist, providing evidence only that his project continues and that his residence changes between Mexico, Canada, Germany, Switzerland, and New York. Each work in this series, which began in 1966, uses the language of the country in which On Kawara was living when he produced it. At first the artist kept "journals" of these works, recording in a three-ring binder the size and date of every painting, samples of the paints he used, and black and white photographs of each painting in the studio or place in which he painted it. Bound newspaper clippings provided social subtitles for the paintings until 1972. Since then the artist has stopped supplementing his rigorously unarticulated subjects, holding back his most recent works to allow them to mature.