However, since they did not take the leap year into account, each year the time of Norouz changed. They then decided to take the leap year into account, as the Persians had nit he pre-Islamic era. Thus originated the Motavakkeli calendar and Mo'tazedi history. It is not exactly known when and how Norouz emerged. Some people believe that natural changes in climate gave birth to Norouz.
Some researchers consider it a national festival, while others regard it as a religious feast.
Therefore, the Zoroastrians honor the ten-day period in order to make the spirits of their deceased ancestors happy. The tradition by some of going to cemeteries before Norouz may have its origin in this belief. Others have narrated tales about the origin of Norouz. One version is that on this day, Kia Khosrow, son of Parviz Bardina, ascended the throne and made Iranshahr flourish. They saw the sun's rays on the king and celebrated the day.