{
  "experiment": "excel-1900-1904-date-systems",
  "executedAt": "2026-10-15T02:00:16.763962+00:00",
  "runtime": "3.14.8",
  "synthetic": true,
  "date": "2026-10-15",
  "serial1900": 46310,
  "serial1904": 44848,
  "differenceDays": 1462,
  "cases": [
    {
      "serial": 46310,
      "system": "1900",
      "decoded": {
        "status": "ok",
        "iso": "2026-10-15T00:00:00"
      }
    },
    {
      "serial": 44848,
      "system": "1904",
      "decoded": {
        "status": "ok",
        "iso": "2026-10-15T00:00:00"
      }
    },
    {
      "serial": 46310,
      "system": "1904",
      "decoded": {
        "status": "ok",
        "iso": "2030-10-16T00:00:00"
      }
    },
    {
      "serial": 44848,
      "system": "1900",
      "decoded": {
        "status": "ok",
        "iso": "2022-10-14T00:00:00"
      }
    },
    {
      "serial": 59,
      "system": "1900",
      "decoded": {
        "status": "ok",
        "iso": "1900-02-28T00:00:00"
      }
    },
    {
      "serial": 60,
      "system": "1900",
      "decoded": {
        "status": "unrepresentable",
        "label": "Excel fictitious 1900-02-29"
      }
    },
    {
      "serial": 61,
      "system": "1900",
      "decoded": {
        "status": "ok",
        "iso": "1900-03-01T00:00:00"
      }
    },
    {
      "serial": "46310.5",
      "system": "1900",
      "decoded": {
        "status": "ok",
        "iso": "2026-10-15T12:00:00"
      }
    }
  ],
  "syntheticWorkbookMetadata": "<workbook xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\"><workbookPr date1904=\"1\"/></workbook>",
  "date1904Flag": "1",
  "scope": "Pure Python conversion plus minimal OOXML metadata parsing; no Excel application or actual workbook opened. Serial60 is explicitly quarantined, not coerced to a real date."
}