The six festivals are additionally associated with the six "primordial creations" of Ahura Mazda, otherwise known as the Amesha Spentas, and through them with aspects of creation (the sky, the waters, the earth, plant life, animal life, humankind).
These apparently caused some confusion, and at some point the old and new festival days were joined as six-day-long observations (later reduced to five).
However, following the collapse of the Sassanian state, after which Zoroastrianism had no central authority to govern intercalation, the practice was not maintained.
As a result, in living Zoroastrianism, the Gahanbar are again no longer synchronous with the seasons.
A special Yasna or Jashan (meaning "worship", "oblation") service is then held in honor of the respective yazata on those day/month intersections.