{"abstract":"When the original due date was moved off a weekend, the extended due date is moved as well.","category":"Legal deadline computation","checks":7,"contract":"Stipulated: a return for a fiscal year ending fy_end (month end) is due on the 15th day of the 3rd month after year end for a partnership and the 4th month for other entities. A statutory date on a weekend or listed holiday moves to the next open day. An extension request filed on or before that (moved) due date extends the due date to 6 months after the statutory (unmoved) date, again moved forward if closed.","contract_signature":"fy_end, entity, requested, holidays","evaluation_group":"w2-legal-deadline-computation-return-due-date-extension","failed_approach":"The partial repair `due - dt.timedelta(days=due.weekday() - 4) if due.weekday() == 0 else due` only undoes the move for Monday due dates and still carries holiday moves into the extension.","family":"w2-legal-deadline-computation-return-due-date-extension-extension-base","id":"FA-77776","implementations":{"attempt":{"sha256":"f65b98b2fe1508bf495bd68512a8f64c5b82228edaf18d1663424f57cfb84f43","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport datetime as dt\nimport calendar\nN = 1\nobservations = []\ndef solve(fy_end, entity, requested, holidays):\n    e = dt.date.fromisoformat(fy_end)\n    hol = {dt.date.fromisoformat(x) for x in holidays}\n    def roll(d):\n        while d.weekday() >= 5 or d in hol:\n            d += dt.timedelta(days=1)\n        return d\n    def plus_months(d, k):\n        mi = d.month - 1 + k\n        return dt.date(d.year + mi // 12, mi % 12 + 1, d.day)\n    statutory = plus_months(dt.date(e.year, e.month, 15), 3 if entity == 'partnership' else 4)\n    due = roll(statutory)\n    if requested is not None and dt.date.fromisoformat(requested) <= due:\n        due = roll(plus_months(due - dt.timedelta(days=due.weekday() - 4) if due.weekday() == 0 else due, 6))\n    return due.isoformat()\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15'),\n  ('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15'),\n  ('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15')],\n [('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15'),\n  ('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15'),\n  ('march fiscal year corporation',\n   ['2024-03-31',\n    'corporation',\n    '2024-07-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2025-01-15'),\n  ('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17')],\n [('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15'),\n  ('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15'),\n  ('march fiscal year corporation',\n   ['2024-03-31',\n    'corporation',\n    '2024-07-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2025-01-15'),\n  ('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17'),\n  ('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15')],\n [('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15'),\n  ('march fiscal year corporation',\n   ['2024-03-31',\n    'corporation',\n    '2024-07-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2025-01-15'),\n  ('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17'),\n  ('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15'),\n  ('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15')],\n [('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17'),\n  ('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15'),\n  ('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15')]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"8b0cf1118a62c2f04654e7b6c7110e082f1fd6de38338f86190c22a13e3105fb","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport datetime as dt\nimport calendar\nN = 1\nobservations = []\ndef solve(fy_end, entity, requested, holidays):\n    e = dt.date.fromisoformat(fy_end)\n    hol = {dt.date.fromisoformat(x) for x in holidays}\n    def roll(d):\n        while d.weekday() >= 5 or d in hol:\n            d += dt.timedelta(days=1)\n        return d\n    def plus_months(d, k):\n        mi = d.month - 1 + k\n        return dt.date(d.year + mi // 12, mi % 12 + 1, d.day)\n    statutory = plus_months(dt.date(e.year, e.month, 15), 3 if entity == 'partnership' else 4)\n    due = roll(statutory)\n    if requested is not None and dt.date.fromisoformat(requested) <= due:\n        due = roll(plus_months(due, 6))\n    return due.isoformat()\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15'),\n  ('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15'),\n  ('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15')],\n [('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15'),\n  ('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15'),\n  ('march fiscal year corporation',\n   ['2024-03-31',\n    'corporation',\n    '2024-07-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2025-01-15'),\n  ('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17')],\n [('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15'),\n  ('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15'),\n  ('march fiscal year corporation',\n   ['2024-03-31',\n    'corporation',\n    '2024-07-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2025-01-15'),\n  ('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17'),\n  ('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15')],\n [('statutory on holiday',\n   ['2023-12-31',\n    'individual',\n    '2024-04-10',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25',\n     '2024-04-15']],\n   '2024-10-15'),\n  ('march fiscal year corporation',\n   ['2024-03-31',\n    'corporation',\n    '2024-07-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2025-01-15'),\n  ('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17'),\n  ('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15'),\n  ('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15')],\n [('september fiscal partnership',\n   ['2023-09-30',\n    'partnership',\n    '2023-12-15',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25',\n     '2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-06-17'),\n  ('regression: statutory saturday, extension',\n   ['2022-12-31',\n    'corporation',\n    '2023-04-17',\n    ['2023-01-02',\n     '2023-01-16',\n     '2023-02-20',\n     '2023-05-29',\n     '2023-06-19',\n     '2023-07-04',\n     '2023-09-04',\n     '2023-10-09',\n     '2023-11-10',\n     '2023-11-23',\n     '2023-12-25']],\n   '2023-10-16'),\n  ('partnership calendar year',\n   ['2023-12-31',\n    'partnership',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-03-15'),\n  ('partnership extension',\n   ['2023-12-31',\n    'partnership',\n    '2024-03-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-09-16'),\n  ('corporation june year',\n   ['2024-06-30',\n    'corporation',\n    None,\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('request on due date',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-15',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-10-15'),\n  ('late request',\n   ['2023-12-31',\n    'corporation',\n    '2024-04-16',\n    ['2024-01-01',\n     '2024-01-15',\n     '2024-02-19',\n     '2024-05-27',\n     '2024-06-19',\n     '2024-07-04',\n     '2024-09-02',\n     '2024-10-14',\n     '2024-11-11',\n     '2024-11-28',\n     '2024-12-25']],\n   '2024-04-15')]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Stipulated toy deadline rules evaluated offline on explicit fixtures. The contract is inspired by common court-rule structures but is not legal advice and makes no claim to reproduce any jurisdiction's rules. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-legal-deadline-computation-return-due-date-extension-extension-base","generated_at":"2026-09-29T14:49:29.038090+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Docketing systems compute filing and response deadlines from trigger events; a wrong date can forfeit a right.","root_cause":"The six months are added to the moved due date instead of the statutory date.","sha256":"1661a6696541f258b4ec742733f3d48b87821b9914d7f55bce78a2447e28fe34","title":"Return due date with automatic extension from the statutory date: extension base · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":47.151,"exit_code":1,"observations":[{"actual":"2023-10-23","check":"regression: statutory saturday, extension","expected":"2023-10-16","passed":false},{"actual":"2024-03-15","check":"partnership calendar year","expected":"2024-03-15","passed":true},{"actual":"2024-09-16","check":"partnership extension","expected":"2024-09-16","passed":true},{"actual":"2024-10-15","check":"corporation june year","expected":"2024-10-15","passed":true},{"actual":"2024-10-21","check":"request on due date","expected":"2024-10-15","passed":false},{"actual":"2024-04-15","check":"late request","expected":"2024-04-15","passed":true},{"actual":"2024-10-16","check":"statutory on holiday","expected":"2024-10-15","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: statutory saturday, extension\", \"actual\": \"2023-10-23\", \"expected\": \"2023-10-16\", \"passed\": false}, {\"check\": \"partnership calendar year\", \"actual\": \"2024-03-15\", \"expected\": \"2024-03-15\", \"passed\": true}, {\"check\": \"partnership extension\", \"actual\": \"2024-09-16\", \"expected\": \"2024-09-16\", \"passed\": true}, {\"check\": \"corporation june year\", \"actual\": \"2024-10-15\", \"expected\": \"2024-10-15\", \"passed\": true}, {\"check\": \"request on due date\", \"actual\": \"2024-10-21\", \"expected\": \"2024-10-15\", \"passed\": false}, {\"check\": \"late request\", \"actual\": \"2024-04-15\", \"expected\": \"2024-04-15\", \"passed\": true}, {\"check\": \"statutory on holiday\", \"actual\": \"2024-10-16\", \"expected\": \"2024-10-15\", \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.239,"exit_code":1,"observations":[{"actual":"2023-10-17","check":"regression: statutory saturday, extension","expected":"2023-10-16","passed":false},{"actual":"2024-03-15","check":"partnership calendar year","expected":"2024-03-15","passed":true},{"actual":"2024-09-16","check":"partnership extension","expected":"2024-09-16","passed":true},{"actual":"2024-10-15","check":"corporation june year","expected":"2024-10-15","passed":true},{"actual":"2024-10-15","check":"request on due date","expected":"2024-10-15","passed":true},{"actual":"2024-04-15","check":"late request","expected":"2024-04-15","passed":true},{"actual":"2024-10-16","check":"statutory on holiday","expected":"2024-10-15","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: statutory saturday, extension\", \"actual\": \"2023-10-17\", \"expected\": \"2023-10-16\", \"passed\": false}, {\"check\": \"partnership calendar year\", \"actual\": \"2024-03-15\", \"expected\": \"2024-03-15\", \"passed\": true}, {\"check\": \"partnership extension\", \"actual\": \"2024-09-16\", \"expected\": \"2024-09-16\", \"passed\": true}, {\"check\": \"corporation june year\", \"actual\": \"2024-10-15\", \"expected\": \"2024-10-15\", \"passed\": true}, {\"check\": \"request on due date\", \"actual\": \"2024-10-15\", \"expected\": \"2024-10-15\", \"passed\": true}, {\"check\": \"late request\", \"actual\": \"2024-04-15\", \"expected\": \"2024-04-15\", \"passed\": true}, {\"check\": \"statutory on holiday\", \"actual\": \"2024-10-16\", \"expected\": \"2024-10-15\", \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}