This article critiques the tendency to periodise television series into particular eras. Using Doctor Who as an example, it argues that, although a convenient shorthand for understanding changes in production staff, regenerations of the main character, or behind-the-scenes script editing, the meaningful articulation of ruptures in the continuity of television series also acts reductively on story interpretation. Periodisation disciplines readings of particular assumptions about eras of any show. This article argues for a more nuanced understanding of the practice of periodisation across television studies, focusing specifically on the archontic principles of the Doctor Who text. Specifically, it argues for the joining of periodisation with continuity and canon as concomitant, polyvocal organisational factors applicable to the understanding of the ontology of any television text.