Use the form below to convert between dates from a Gregorian calendar to a Shenshai calendar (or vice-versa). For example, you can use this to find the roj for a particular date (such as your birthday), as well as what date the roj falls on in a given year. Alternatively, you can see what date a given roj falls on in any year.
About Zoroastrian Calendars
The Shenshai Calendar
In the Shenshai calendar, a year consists of 12 months, or mahs, and each month has 30 days. Each of these days is known as a roj, and each roj has a name. As 30 days * 12 months = 360 days, there are an additional 5 days (gathas) added to the 12th month to make a 365 day year.
A solar calendar, however, is around 365 1/4 days, which the Gregorian calendar accommodates by adding a day every four years (leap day). Because of this difference, the Zoroastrian calendar and solar year began to diverge. In 1006 C.E. the Zoroastrian calendar and solar year once again aligned, resulting in Navroze occuring on the Vernal Equinox. It was then decided that an extra month was to be added every 120 years to accommodate for the difference between the solar year and the Zoroastrian calendar year.
The Zoroastrians in India (Parsis) last remembered to add this extra month in 1129 C.E. Consequently, New Year, which originally correlated with the vernal equinox on March 21st, has since fallen earlier in the Gregorian calendar year such that it now occurs in August.
The Kadmi Calendar
While the Zoroastrians in India intercalated an extra month to the calendar around 1129 C.E., the Zoroastrians in Iran did not, causing the calendar used by the Iranian Zoroastrians to be ahead by a month. This discrepency was brought to the attention of the Indian Zoroastrians by a visiting Iranian priest in the 1700s. A group of Indian Zoroastrians (the Kadmi or Qadimi) decided to follow the Iranian calendar, believing it to be more authentic.
The Fasli Calendar
In the early twentieth century, Khurshedji Cama devised the Fasli Calendar, which maintained alignment with the seasons such that New Year's day coincides with the vernal equinox. Similar to the Shenshai and Kadmi calendars, it consists of 12 months of 30 days with an additional 5 days (gathas), but intercalates a leap day called Avardad-sal-Gah every four years (patterned after the Gregorian calendar's leap day).
Problems, Errors, Suggestions: If you find problems or inaccuracies with the calculations, please let me know so that I can try to fix them. Send me as much detailed information as possible, including the browser version you are using, the dates you entered, what you expected, etc. Similarly, suggestions for improving the calendar are also welcome. Send feedback using the contact form.
Disclaimer: I hope that this little conversion utility has been useful, but I make no claims nor accept any liability about its accuracy, quality, availability, etc.
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