Ushahin completes a structure worth standing back from. Across the five gahs the Zoroastrian day assigns every hour a guardian and every guardian a greeting, and the night watch shows the system's purpose most nakedly, because night is where the system is tested. Zoroastrian dualism takes darkness seriously: the hours from midnight to dawn belong, in the tradition's cosmology, to the counter-creation's strongest efforts, the time when corpse-pollution walks and the frost demon works.
The response is not avoidance but garrison. Sraosha stands guard; the priesthood, on the nights it performs the Vendidad service, stands with him; the souls of the dead are prayed for in this watch, whose third night after death is when the soul faces its judgment at the Chinvat bridge, making Ushahin the traditional time for the funerary ceremonies of the third night; and any believer who wakes joins the line with a prayer.
Boyce's fieldwork in the Iranian villages recorded the practice's domestic texture, elderly Zoroastrians rising in the night to pray as their ancestors had, and the diaspora keeps the watch where sleep allows. Set beside the Christian night office and the Muslim tahajjud, the Ushahin Gah is the oldest member of a small family of institutions that refuse to concede the night, and its wager is the same as theirs: that a tradition which prays in the dark owns the whole day, not just the lit part of it.