Yalda is the only other festival, apart from Now Rooz, that is celebrated by modern day Zarathushtis at its proper time.
All ancient Zarathushti festivals were the celebration of the landmarks in the journey of the earth around the sun and the seasonal events in nature. It shows that they had precise knowledge about the earth and its movement around the sun, thousands of years before Galileo and the western world accepted the truth.
Deygan or Yalda, is the celebration of the winter Solstice and its highlight is the longest night. It is the start of the winter season, which lasts for 88.9 days and is the shortest season.
In Mithraism, this day was celebrated as the birth of the Sun because from the next day, the days get longer and according to them, the sun is growing. They called this day “Zayesh e Mehr” – Birth of Mehr.
The name Yalda is Syrianic translation of the same, coined by the Assyrian Christians who replaced the Sun God with the Son of God. With the genocide of the Zarathushtisii to the point of annihilation and the persecution of the remaining few by Islam, there was neither the disposition nor possibility for festivity and so the significance of most of the ancient festivals was lost.
Yalda lost even its original name and when revived, they adopted the Syrianic name. Those who are not happy with the name call it “Shab e Chella”, because 40 (Chel) days later is the festival of Sadeh.
Logically just as “Tirgan” is the name of the summer Solstice, Deygan must have been the name of the winter Solstice, as both happen on the first day of their respective month, in this case “Dey”.
Scholars, under the influence of documents compiled during the Islamic period, that strive to depict Zarathushtis as dualist and superstitious worshipers of Izad’s, have connected the Zarathushti festivals to the celebration of Izad’s and replaced the science with superstition, which in turn has been believed by modern day Zarathushtis for lack of better information.
Just like in the case of the “Now Rooz Table” that used to represent the “Seven Eternal Laws” given in the Gathas, has been manipulated to focus on, seven items starting with the letter “S” (of no significance and with superficial philosophy).
Ironically, the Persian name of some of these items does not start with “S” and so their Arabic name is used instead. For that matter even, the Amasha Spenta have been diluted to represent the attributes of a human like God, the “Anthropomorphic God” that Herodotus rightly says the Persians did not believe in.
Zarathushtra, who has so accurately calculated the natural meridian (Mehr Yasht Ha103-104) and named it “Nim Rooz” could not have subsisted with any of the three modern Zarathushti calendars.
The festivals vouch for the accuracy of the ancient Mazdayasni calendar, which divides the year into four unequal but natural parts based on the revolution of the earth around the sun. According to the ancient Mazdayasni calendar , the year starts with the Vernal Equinox – Now Rooz, followed by Tirgan the summer Solstices on the 92.8th day, Mehregan the Autumn Equinox on the 186.4th day and Deygan (Yalda) the winter Solstice on the 276.3rd day.
Each of these unequal periods individually divided gives us 31 days each for the first 6 months and 30 days for the next five months, with the balance of days before the Vernal Equinox constituting the last month, which could be 29 or 30, whereby the leap year is automatically taken care of with no need for intercalation.
The celebration of Deygan’s long winter night involved the recitation and discussion of the Gathas, which on revival of the festival by the Iranians, was replaced by, the recitation of the 14-century poems of Hafez; today Zarathushtis do the same.
It is time for all Zarathushtis, to let Mazda (Wisdom) rule, adopt the ancient Mazdayasni calendar, and celebrate the festivals when it happens in nature and let go of the superstitions that have been forced upon them.
Let the world know that thousands of years before Galileo our ancestors knew of the real relation between the Sun and the Earth. They studied nature, learned from it, celebrated it, respected it and took care of the environment.
May Mazda Prevail.