Qadimi (IRST)

Overview

The Qadimi calendar is a calculated solar calendar of Zoroastrianism. It was intended to follow the Spring Equinox, but a lack of intercalary days has resulted in this calendar drifting significantly.

It features 12 months of 30 days, plus a period of 5 days at the end of each year called the Gatha days. Each of the 30 days of the month are named, as well as each of the Gatha days. Days start at sunrise in Iran.

Years are denoted with 'Y.Z.' for the 'Yazdegerdi era', a count of years since the accession of the last Sassanid ruler, Yazdegerd III, but there have been several epochs used in the past.

Compared to the Gregorian calendar, the Qadimi calendar drifts by about 1 day every 4 years.

Info

Accuracy

This calendar is a simple calculation with a known epoch. However, historically this calendar has received many revisions, particularly prior to 1006 CE, so the dates here might not accurately reflect historical dates.

Source

Common Source

Wikipedia article

Primary Sources

Zoroastrian website

This calendar can be calibrated using the calculator at this site.