Nizam al-Mulk's Reform of the Calendar

إصلاح نظام الملك التقويم

c. 1079 CE · c. 471 AH

Under al-Muqtadi, Nizam al-Mulk gathered the astronomers and made Nawruz the first point of Aries — it had been at the sun's entry into mid-Pisces — and what Nizam did became the origin of the calendars 1.

Depth

At a glance

Era
Abbasid Fragmentation
Region
Persia & Central Asia
Review
Draft Completeness 2/5 · Help complete it

In time

107010801090 c.
The Buyid, Fatimid and Seljuk Era

Summary

In the days of the caliph al-Muqtadi, Nizam al-Mulk gathered the astrologers, who fixed Nawruz at the first point of Aries. 2

The change

Before this, Nawruz fell when the sun entered the middle of Pisces. The source says that what Nizam al-Mulk did became the basis of the calendars. 2

The source does not specify the year; it is approximately 471 AH, during the caliphate of al-Muqtadi. This needs an additional source.

Connections

Explore the connections

Had participant
نظام الملك وزير ألب أرسلان

People and things also explored

The Nizamiyya Madrasa of Baghdad· The sakk and the hawala· The killing of Sultan Alp Arslan and the accession of Malikshah· وضع التقويم الجلالي في عهد ملكشاه· The Founding of the Nizamiyya in Baghdad· The Nizamiyya of Nishapur· The Strife over Declaring the Hanbalis Unbelievers and the Looting of the Nizamiyya Market· Mu'ayyid al-Mulk Abu Bakr ibn Nizam al-Mulk

Sources

  1. Tarikh al-Khulafa — al-Suyuti (Dar al-Minhaj edition) , p. 650
  2. Tarikh al-Khulafa — al-Suyuti (Dar al-Minhaj edition) , p.650
Cite this page

islam.museum contributors. “Nizam al-Mulk's Reform of the Calendar”. islam.museum, https://islam.museum/en/event/nizam-mulk-calendar-reform/. CC BY-SA 4.0. Last updated 2026-10-22.

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Related

The Nizamiyya Madrasa of Baghdad

The Nizamiyya of Baghdad, first and most famous of the madrasas founded by the vizier Nizam al-Mulk al-Tusi: building began in 457 and sisters rose at Nishapur, Isfahan, Herat, Basra, Mosul and Amid; the Imam al-Haramayn al-Juwayni then Abu Ishaq al-Shirazi taught in it, and it mothered the Sunni institutional model that the later madrasas of Baghdad followed — the caliphs prayed there and Nizam al-Mulk himself visited to inspect its library.