{
  "application": "quranml",
  "version": 1,
  "retrieved_date": "2026-11-06",
  "runtime": "Browser-local arithmetic and pinned numerical table; no calendar service requests",
  "range": {
    "min_jd": 347997.5,
    "max_jd": 5373483.5,
    "gregorian_astronomical_min": [
      -3760,
      9,
      7
    ],
    "gregorian_max": [
      9999,
      12,
      31
    ]
  },
  "conventions": {
    "gregorian": "Proleptic Gregorian; astronomical year zero = 1 BCE; no regional reform gap",
    "persian": "Astronomical Solar Hijri, 52.5 degrees east, apparent-noon rule; signed years include zero; long-range estimates use VSOP87 and extrapolated DeltaT; no 2820-year arithmetic substitution",
    "hebrew": "Proleptic fixed Hebrew calendar; year >=1; Nisan1 through AdarII13; AdarII only in leap years",
    "islamic": "Tabular civil Hijri; Friday epoch, JD1948439.5; signed proleptic years; not Umm al-Qura or observed moon sightings",
    "ethiopian": "Amete Mihret; epoch JD1724220.5; 13th month has 6 days when year modulo4=3, otherwise5",
    "mayan": "GMT584283; epoch civil midnight JD584282.5; Long Count plus Haab/Tzolkin; unavailable before epoch",
    "julian": "Proleptic Julian calendar; astronomical year zero = 1 BCE",
    "jd": "Input fraction preserved; displayed civil midnight floor(inputJD+0.5)-0.5; integer Julian day begins at noon",
    "mjd": "JD minus2400000.5; integer MJD begins at midnight"
  },
  "limits": [
    "Date-only conversions do not determine local sunset or historical/religious observance.",
    "Long-range Persian dates are numerical astronomical estimates, with uncertain extrapolated Earth rotation; no uniform ephemeris accuracy claim."
  ],
  "sources": [
    {
      "title": "convertdate 2.4.0 source",
      "url": "https://github.com/fitnr/convertdate/tree/v2.4.0/src/convertdate",
      "license": "MIT; copyright 2014–2022 Neil Freeman",
      "notice": "vendor/LICENSE-convertdate.txt"
    },
    {
      "title": "PyMeeus 0.5.12 offline astronomical authoring tool",
      "url": "https://pypi.org/project/PyMeeus/0.5.12/",
      "license": "LGPLv3; upstream program not distributed in browser assets"
    },
    {
      "title": "NASA DeltaT polynomials and limits",
      "url": "https://eclipse.gsfc.nasa.gov/SEhelp/deltatpoly2004.html"
    },
    {
      "title": "Unicode ICU calendar source/tests",
      "url": "https://github.com/unicode-org/icu/blob/main/icu4c/source/test/intltest/caltest.cpp"
    },
    {
      "title": "US Naval Observatory Islamic calendar",
      "url": "https://aa.usno.navy.mil/faq/islamic"
    },
    {
      "title": "Smithsonian Living Maya Time",
      "url": "https://maya.nmai.si.edu/calendar/maya-calendar-converter"
    },
    {
      "title": "Hebcal fixed Hebrew date conversion",
      "url": "https://www.hebcal.com/converter?hy=2448&hm=Sivan&hd=6&h2g=1"
    }
  ],
  "authoring_source_archives": [
    {
      "package": "convertdate",
      "version": "2.4.0",
      "url": "https://files.pythonhosted.org/packages/04/3d/04148ceb732dfb6f10e9b89fa5915080a91e27fe28fd982c259bc4d29ced/convertdate-2.4.0.tar.gz",
      "sha256": "770c6b2195544d3e451e230b3f1c9b121ed02680b877f896306a04cf6f26b48f"
    },
    {
      "package": "PyMeeus",
      "version": "0.5.12",
      "url": "https://files.pythonhosted.org/packages/81/76/599896b37e60f43078afd8354b3802eb7ca257a7e7f6253cc21c4c672877/PyMeeus-0.5.12.tar.gz",
      "sha256": "548f7186bd8b96cbc069cf649a8e8e377dce49ac74486709849fe63a99cad684"
    }
  ],
  "persian_table": {
    "path": "vendor/persian-year-starts.mjs",
    "sha256": "bc31ca3a4f9c36981f34b0da31d97ddb1b92378126f62c713180faa80365b6d3",
    "bytes": 14824,
    "first_year": -4381,
    "last_boundary_year": 9379,
    "boundary_count": 13761,
    "generation_seconds": 163.109,
    "authoring": "vendor/generate-persian.py",
    "full_method_notes": "vendor/provenance.md",
    "data_kind": "Generated numerical year boundaries; no upstream program text or application data"
  },
  "verification": {
    "committed_test_assertions": 49932,
    "fresh_upstream_comparisons": 1832,
    "fresh_upstream_sample_days": 370,
    "node": "v24.18.0",
    "icu": "78.3",
    "notes": "Upstream comparisons and internal round trips are distinct from independent astronomical accuracy."
  }
}