{
  "function": "ISOYEAR",
  "software": "Gnumeric",
  "guide": "/gnumeric/functions/isoyear/",
  "review_date": "2026-10-12",
  "scope": "Selected example checks, not certification of every formula, error, locale or cross-application import/export.",
  "native_engine": null,
  "native_assertions": 0,
  "native_observations": 0,
  "native_cases": [],
  "independent_model_cases": [
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2000-01-01",
      "formula": "",
      "actual": 1999,
      "expected": 1999,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2008-01-01",
      "formula": "",
      "actual": 2008,
      "expected": 2008,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2016-01-01",
      "formula": "",
      "actual": 2015,
      "expected": 2015,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2019-12-30",
      "formula": "",
      "actual": 2020,
      "expected": 2020,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2020-12-31",
      "formula": "",
      "actual": 2020,
      "expected": 2020,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2021-01-01",
      "formula": "",
      "actual": 2020,
      "expected": 2020,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2021-01-04",
      "formula": "",
      "actual": 2021,
      "expected": 2021,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2024-12-30",
      "formula": "",
      "actual": 2025,
      "expected": 2025,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "2026-12-31",
      "formula": "",
      "actual": 2026,
      "expected": 2026,
      "passed": true,
      "method": "Python datetime ISO calendar",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "Thursday shift 2021-01-01",
      "formula": "",
      "actual": 2020,
      "expected": 2020,
      "passed": true,
      "method": "Gregorian Thursday-shift arithmetic",
      "native_application": false
    },
    {
      "software": "gnumeric",
      "function": "ISOYEAR",
      "case": "Thursday shift 2019-12-30",
      "formula": "",
      "actual": 2020,
      "expected": 2020,
      "passed": true,
      "method": "Gregorian Thursday-shift arithmetic",
      "native_application": false
    }
  ],
  "documented_expected_results_not_native": true,
  "sources": [
    "https://gnome.pages.gitlab.gnome.org/gnumeric/manual/CATEGORY_DateTime.html#gnumeric-function-ISOYEAR",
    "https://github.com/GNOME/gnumeric/blob/GNUMERIC_1_12_62/plugins/fn-date/functions.c",
    "https://gnome.pages.gitlab.gnome.org/gnumeric-web/functions.shtml",
    "https://download.gnome.org/sources/gnumeric/1.12/",
    "https://support.microsoft.com/en-us/office/isoweeknum-function-1c2d0afe-d25b-4ab1-8894-8d0520e90e0e",
    "https://help.libreoffice.org/latest/en-US/text/scalc/01/func_weeknum.html"
  ]
}