Time is often one of the more important variables to be displayed in a chart, and it can be placed as a positional dimension, giving it a high visual impact and affording the user the strongest ability to make comparisons. However, in other situations time is not the focus of a visualization – the goal is to show some other features of the data instead. In such a situation time may be of secondary importance; we do not want to make large changes to the chart to display time, but we do want to show it as an additional feature that may help viewers understand the data better. In such a case, we can portray time using an aesthetic, a visual property of a graphical element that represents a variable. In this chapter the focus of the discussion is on enhancing a visualization that is nontemporal in nature by adding an aesthetic that shows time.