In 1987 Nancy Holt developed several proposals for outdoor sculpture at the University of Massachusetts Dartmouth (formerly Southeastern Massachusetts University, SMU) that remained unrealized: this sculpture Time Lines, Solar Crossings, and Sun Cuts. Later, in 1991, she realized the sculpture Spinwinder on the campus. Circular structures, cardinal and solar orientations, earth forms, and the marking of astronomical time recur across the three proposals.

These drawings and model are for the proposal Time Lines, developed for the New Science Building on campus. Organized around a circular structure aligned with the cardinal directions, the sculpture incorporated poles of varying heights whose shadows marked particular dates and solar events. Holt calculated the positions of shadows at particular times on the summer and winter solstices, as well as on dates connected to the history of the university. One alignment marked June 9, which Holt identified on the drawing as “the day in 1969 when SMU became a University.”