The art of Caspar David Friedrich (1774–1840) received increased attention in the year 2024, when major exhibitions and other events commemorated the 250th anniversary of his birth. Astronomers have always taken a special interest in his paintings of spectacular twilight scenes that often feature crescent Moons or full Moons. Does Abbey in the Oak Wood, one of Friedrich’s most important works, depict morning twilight or evening twilight? Does the lunar disk in the sky represent a waning crescent Moon or a waxing crescent Moon, and can we determine a calendar date corresponding to this scene? His Greifswald in Moonlight includes a full Moon perfectly aligned with the top of a prominent church tower. Could we determine the location from which Friedrich obtained this view, and could we determine a date for this scene? In Friedrich’s The Evening Star, dramatic twilight hues fill the heavens as three people pass through fields. A boy runs ahead. What city is depicted, and can we identify the towers on the horizon? If we assume that the artist observed Venus high in the sky, and if we identify Friedrich’s son Gustav Adolf as the boy running ahead, then what is the only possible time for the inspiration of The Evening Star?