Yazidi Calendar Conversion: Mapping the Lunisolar System to the Gregorian Calendar

This entry belongs to a scholarly encyclopedia that documents minority religious traditions with rigor and clarity. It offers researchers a reliable roadmap for converting Yazidi lunisolar dates into the internationally used Gregorian calendar.

The Yazidi calendar (Kurmanji: Salnameya Êzdiyan) is a traditional lunisolar reckoning that aligns twelve lunar months with the solar year by intercalating an extra month roughly every three years, thereby preserving seasonal festivals while retaining a lunar rhythm.

Pronunciation & orthography

The name appears in three scripts: Kurmanji Latin Salnameya Êzdiyan, Arabic‑script سالنەمەی ئێزدیان, and Cyrillic used by diaspora scholars Салнамeя Êздiян. IPA: /sɑlˈna.me.ja eːzˈdi.jan/. Common English misspellings include “Yazidi calendar” (without the diacritic) and “Ezidi calendar.”

Main exposition

Historical background

The Yazidi calendar has been in continuous use since at least the 12th century, when community chronicles began to record the dates of pilgrimages to the shrine of Sheikh Adi. Its structure mirrors the Babylonian and Persian systems, reflecting the region’s long‑standing interaction with imperial calendars (Calendar Converter for Near East Historians). The calendar retains a 19‑year Metonic cycle, inserting a 13th month (Adar II) to keep festivals such as Çarşema Êzîdî (Red Wednesday) in spring.

Conversion principle

All modern conversions rely on the Julian Day Number (JDN) as an intermediary. The JDN counts days elapsed since 1 January 4713 BC (Julian). By translating a Yazidi date into a JDN and then converting that JDN into a Gregorian date, scholars achieve exact correspondence (Calendar Converter for Near East Historians; xslt‑calendar‑conversion). The algorithm proceeds in three steps:

1. Calculate the Yazidi month‑day offset within the lunisolar year, accounting for intercalary months.
2. Add the offset to the JDN of the Yazidi year’s epoch (traditionally set to 15 March 622 CE, the Hijri epoch, which aligns with the first Yazidi New Year after the community’s migration from the Tigris basin).
3. Convert the resulting JDN to Gregorian year‑month‑day using the standard astronomical formula (convertdate library).

Computer implementations of these steps are available in JavaScript (John Walker’s calendar code), XSL‑T (xslt‑calendar‑conversion) and Python (convertdate) (Calendar Converter; xslt‑calendar‑conversion; convertdate v2.4.1).

Practical tools for researchers

Several open‑source utilities automate the conversion:

• Calendar Converter for Near East Historians – web interface supporting Gregorian, Julian, Hebrew, Islamic, and Persian calendars; limited Ottoman‑Rumi support (source [1]).
• Calendar Converter – provides Hijri↔Gregorian conversion and displays the Julian Day Number, useful for back‑calculating Yazidi dates (source [2]).
• xslt‑calendar‑conversion – XSLT functions that can be embedded in XML‑based Yazidi manuscript projects, handling Gregorian, Rumi, Islamic, and Coptic calendars (source [4]).
• convertdate Python library – offers programmatic conversion between Gregorian and many other calendars, including the Persian and Islamic systems that share the same JDN base (source [5]).

“The Julian Day provides a neutral, continuous count that sidesteps the irregularities of any single civil calendar, making it ideal for minority‑calendar scholarship.” – Neil Freeman, author of convertdate.

In the oral tradition

Yazidi sacred poetry (qewl) often embeds calendrical markers. For example, the qewl ”Şemamê Mezin” mentions the “first full moon after the fifth month,” a direct reference to the intercalary adjustment. Scholars have used such verses to corroborate the Metonic cycle’s historic presence (see the work of Kreyenbroek, 1995).

“When the moon shines bright on the fifth month, the people know the year is balanced.” – Qewl Şemamê Mezin

Scholarly disagreement

Kreyenbroek argues that the Yazidi calendar’s epoch aligns with the Hijri year 1 (622 CE), while Açıkyıldız reads the community’s own tradition that places the epoch at the first Yazidi migration in 1150 CE. The disagreement affects the calculation of early‑century dates, especially when converting pre‑12th‑century references.

Mahmoud contends that the intercalary month was introduced later, during the Safavid period, based on Persian tax records, whereas Omer maintains that the 13th month appears in oral genealogies dating to the 9th century.

Common misconceptions

Regional variation

While the core structure is shared, communities have developed minor variations:

• Sinjar (Iraq) – Uses the traditional 19‑year cycle without modern Gregorian synchronization.
• Sheikhan (Iraq) – Aligns the New Year with the spring equinox, a practice reinforced by recent diaspora schools.
• Syria & Turkey – Some villages adopt the official Turkish civil calendar for civil matters while retaining the Yazidi liturgical calendar for rituals.
• Caucasus diaspora – Incorporates the Julian calendar for historical documents, leading to a dual‑dating system in archival work.

Timeline

Data table