Darboven lived in New York between 1966 and 1968 where she was in contact with representatives of Minimal Art, such as Sol Lewitt and Carl Andre, among others. Her first abstract geometric constructions on graph paper, which she varies serially, emerged during that time. Contrary to the lack of reference dogmatically demanded by Minimal Art, Darboven soon begins to refer again to concrete contents and circumstances, whereby the visualization of time sequences becomes a central theme of her work. She does this by developing her own notation systems in which numbers – which she regards as the only real invention of man – play a central role. Her early major work, the installation One Century (Library), 1970/71, is based on traditional calendar dates. She systematizes them according to a personal set of rules on sheets of paper which she groups in folders: From the numbers of days, months, years and centuries, she forms cross sums and translates these into geometric forms. The extension of time can thus be experienced both as a linear sequence and in the form of tabular figures, whereby Darboven repeatedly emphasizes the central significance of the aesthetic qualities of her notations.
From the mid-1970s, concrete contents of human cultural and political history appear in the form of text quotations, drawings, prints or photographs in Darboven’s visualizations of the temporal passing of time. These are presented without hierarchy or commentary, but one can read a warning commitment between the lines – not least against the background of German 20th century history. Materials on the Bismarck period, speeches by Willy Brandt or articles in the magazine Der Spiegel, texts by Heinrich Heine, Charles Baudelaire, Rainer Maria Rilke or Jean Paul Sartre as well as photographic and graphic representations of cultural and scientific achievements can become starting points for a critical reflection on the past.