From the exhibition Many Things Placed Here and There: The Dorothy and Herbert Vogel Collection at the Yale University Art Gallery:

In his 1967 essay “Paragraphs on Conceptual Art,” Sol LeWitt wrote, “Most ideas that are successful are ludi­crously simple.” A Square for Each Day of the Seventies is based on a simple idea: the square, a basic geometric unit, is repeated once for each day of the 1970s. The repeated squares form an unfinished grid and thus a larger, imperfect square. In modern art, the grid is typically seen as flat, geometric, and orderly—a minimal statement that does not refer to the outside world. However, by connecting his grid to the calen­dar, an ordered system in and of itself, LeWitt injects the form with a sense of time and reality. It deserves mention that the period of time evoked by this work was the decade in which the Vogels’ collection began to take shape and receive recognition.