Omar Khayyam's Solar Calendar Reform

1079 CE · İsfahan, İran · cultural

The astronomical commission convened by order of Sultan Malik-Shah created, under the leadership of Omar Khayyam, a new solar calendar: the Jalali calendar (Takvim-i Celali).

Held to be more precise than the Gregorian calendar, it rests on a calculation of 8 leap years within a 33-year cycle. Omar Khayyam was also renowned as a mathematician and as the poet of the Rubaiyat.

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Frequently asked questions

What was Omar Khayyam's Solar Calendar Reform?
The astronomical commission convened by order of Sultan Malik-Shah created, under the leadership of Omar Khayyam, a new solar calendar: the Jalali calendar (Takvim-i Celali).
When did Omar Khayyam's Solar Calendar Reform happen?
1079 CE
Where did Omar Khayyam's Solar Calendar Reform take place?
İsfahan, İran