{
 "id": "event/jalali-calendar-reform-467",
 "class": "event",
 "slug": "jalali-calendar-reform-467",
 "label": {
  "ar": "التقويم الجلالي بأمر ملكشاه",
  "en": "The Jalali calendar reform"
 },
 "summary": {
  "ar": "أمر السلطان ملكشاه عمر الخيام وفريقاً من علماء الفلك بإصلاح التقويم فوضعوا التقويم الجلالي بمرصد إصفهان نحو سنة 467هـ/1079م {cite:mawsuat-a3lam-ulama-adaba}.",
  "en": "Sultan Malik-Shah charged Umar Khayyam and a team of astronomers with reforming the calendar; at the Isfahan observatory they produced the Jalali calendar about 467/1079 {cite:mawsuat-a3lam-ulama-adaba}.",
  "ur": "سلطان ملک شاہ نے عمر خیام اور ماہرین فلکیات کی ٹیم کو تقویم کی اصلاح کا حکم دیا؛ اصفہان کے رصد گاہ نے 467ھ/1079ء میں جلالی تقویم بنایا {cite:mawsuat-a3lam-ulama-adaba}."
 },
 "stub": false,
 "wings": [
  "time"
 ],
 "regions": [
  "persia-central-asia"
 ],
 "periods": [
  "period/buyid-seljuk-fatimid-era"
 ],
 "tags": [],
 "aliases": [],
 "themes": [],
 "span": {
  "earliest": 1074.0007666139618,
  "latest": 1075.999438729032
 },
 "display": {
  "start": {
   "edtf": "1074/1075",
   "hijri": "0467",
   "precision": "year",
   "status": "tradition",
   "derived": true,
   "note": "Hijri year 467 as in the record id; the Gregorian range is converted from it (derived)"
  },
  "end": {
   "edtf": "1074/1075",
   "hijri": "0467",
   "precision": "year",
   "status": "tradition",
   "derived": true,
   "note": "Hijri year 467 as in the record id; the Gregorian range is converted from it (derived)"
  }
 },
 "data": {
  "kind": "publication",
  "date": {
   "start": {
    "edtf": "1074/1075",
    "hijri": "0467",
    "precision": "year",
    "status": "tradition",
    "derived": true,
    "note": "Hijri year 467 as in the record id; the Gregorian range is converted from it (derived)"
   },
   "end": {
    "edtf": "1074/1075",
    "hijri": "0467",
    "precision": "year",
    "status": "tradition",
    "derived": true,
    "note": "Hijri year 467 as in the record id; the Gregorian range is converted from it (derived)"
   }
  },
  "sources": [
   "source/mawsuat-a3lam-ulama-adaba"
  ],
  "provenance": {
   "layer": "own-research",
   "source": "written for the Timeline Explorer Umar Khayyam story from the cited source",
   "generated_by": "Devin (SWE-2 Medium)",
   "run": "explorer-khayyam"
  },
  "status": {
   "review": "draft",
   "completeness": 2,
   "generated_by": "Devin (SWE-2 Medium)"
  }
 },
 "prose": {},
 "degree": 4,
 "contemporaries": [],
 "updated": "2026-10-29",
 "connections": [
  {
   "to": "person/umar-khayyam",
   "type": "had_participant",
   "inverse": true,
   "role": "رئيس فريق التقويم",
   "sources": [
    "source/mawsuat-a3lam-ulama-adaba"
   ]
  },
  {
   "to": "place/isfahan",
   "type": "occurred_at",
   "inverse": false,
   "sources": [
    "source/mawsuat-a3lam-ulama-adaba"
   ]
  }
 ],
 "related": [
  "building/jame-masjid-isfahan",
  "event/conquest-of-isfahan",
  "event/death-bahlawan-582",
  "event/khayyam-algebra-treatise",
  "event/killing-of-mardawij-323",
  "event/masud-takes-isfahan-423",
  "event/muhammad-tapar-batiniyya-fort-500",
  "event/mungli-killed-aghlamish-610"
 ],
 "license": {
  "prose": "CC BY-SA 4.0",
  "data": "CC0 1.0"
 }
}