It is commonly assumed that line 2 of Aristophanes' Thesmophoriazusae, where it appears that the action of our play begins in the early morning after dawn, is inconsistent with lines 277-9, where the Kinsman is told to hurry off to the women's Assembly so as to arrive there before dawn (cf. 376). This article offers a fresh approach to the problem by re-analyzing the temporal co-ordinate offered by the Kinsman's wish for the appearance of χελιδων, 'the swallow', in line 1. It is argued that for an audience of mid-April 411, the play's production date, χελιδων did not primarily evoke the coming of spring as is usually presumed. Rather, the word evoked a specific time of night, the pre-dawn hours of ορρος, during which, in April 411, not only the swallow could be heard but also a star called Χελιδων could be seen ascending before sunrise. The Kinsman's reference to χελιδων therefore situates the beginning of the play at some unspecified time before dawn, implying that Euripides and his Kinsman have been tramping around in circles ever since the dawn of the day before, and that the dawn of line 376 is the dawn of a second day. The twenty-four hour wandering of our play's protagonists in search of a solution to Euripides' predicament therefore provides a comic precedent for Alcibiades' description of Socrates' twenty-four-hour, dawn-to-dawn, stint of philosophizing in Plato's Symposium (220c3-d5).