In 656, The Gnomon of Zhou (Zhoubi 周髀) was canonised as one of The Ten Mathematical Classics (Suanjing shishu 算經十書) that would serve as the basis of contemporary curricula and testing and, later, the study of the history of mathematics in ancient China. More specifically, The Gnomon of Zhou was canonised as the first of said classics, and scholars ever since have treated it as the earliest of its kind, most today following Qian Baocong (1968) in positing that it was redacted from earlier materials circa 100 BCE. In this paper, I will present linguistic evidence that supports Christopher Cullen (1996) and early Qian Baocong’s (1924; 1932) position that the received Gnomon of Zhou came together much later, in the first or second century CE, at around the same time or later than The Nine Chapters on Mathematical Procedures (Jiuzhang suanshu 九章算術). In addition, I will present evidence connecting its early reception and transmission history to the far north / north-west that might explain features of this strange text and its strange position discussions of cosmology in the Middle Period Chinese capitals further south.