Dear Bahá'í Friend,
The Universal House of Justice has asked us to convey the following in reply to your letter of April 6 [1979].
1. Regarding the beginning of the Zoroastrian era, in one of His Tablets 'Abdu'l-Bahá states that Zoroaster lived about 750 years after Moses. In a letter to an individual believer the Guardian's secretary wrote on his behalf: "Zoroaster lived about a thousand years before Christ. There is no exact date in the teachings regarding the beginning of His Dispensation."
2. Concerning your second question referring to a purported Tablet of the Bab stating that there were thirty Zoroasters, the Research Department states that no text from the Bab has been found on this subject. However, Mirza Abu'l-Fadl has stated in his writings that there appeared in Iran many prophets prior to the Dispensation of Zoroaster.
With loving Bahá'í greetings,
For Department of the Secretariat
(Baha’i Library Online)