not known, but it is generally accepted that he was born in the beginning of the first millennium BC.
The date of birth of Zarathushtra is also not precisely known, and the date of Khordad Sal as his birthday is symbolical.
Khordad Sal is celebrated with clean homes, new clothes, fragrant flowers and delicious meals. Jashan, or thanksgiving prayers, are offered to God. The festival is also an opportunity for the Parsis to review their lives and actions, and make resolutions for the future.