The older part of the Yasna Haptanghaiti is generally considered to have been composed by the immediate disciples of Zoroaster, either during the prophet's lifetime or shortly after his death.
Joanna Narten (Narten 1986) has suggested that, like the Gathas, the hymns of the Yasna Haptanghaiti were composed by Zoroaster himself, but this hypothesis has not received a significant following from the academic community.
In substance, the seven chapters are of great antiquity and contain allusions to the general (not necessarily Zoroaster-influenced) religious beliefs of the period in which Zoroaster was himself a priest.
The texts are thus also of significance to scholars of religious history, and play a key role in the reconstruction of (Indo-)Iranian religion and for distinguishing Zoroaster's contributions from previously existing ideas and beliefs.
Analysis of the texts suggests that the hymns of the Yasna Haptanghaiti were composed as a discrete unit.