{"abstract":"Month lengths are approximated by thirty days.","category":"Calendar arithmetic","checks":4,"contract":"Valid ISO Gregorian dates in years 1 through 9999; generated dates must remain in that range. Month is 1 through 12 and zero-based weekday is Monday 0 through Sunday 6 unless the output convention says otherwise. Ordinal day of year. Exact operational definition: date.fromisoformat(text).timetuple().tm_yday","contract_signature":"text","evaluation_group":"model-db30666d45731657","failed_approach":"A zero-based elapsed-day count is returned under a one-based ordinal contract.","family":"xn-ordinal-day-of-year","id":"FA-6486","implementations":{"attempt":{"sha256":"b15d6a74a41e65e0f9bdf3943cb907b7a4d611750be9aa8c239a10bd5da39dff","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nimport calendar\nimport statistics\nimport itertools\nfrom fractions import Fraction\nfrom datetime import date, datetime, timedelta, timezone\nfrom decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR\n\nN = 1\nobservations = []\ndef solve(text):\n    return (date.fromisoformat(text)-date(date.fromisoformat(text).year,1,1)).days\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck(\"fixture 1: ('2024-03-01',)\", solve(*('2024-03-01',)), 61)\ncheck(\"fixture 2: ('2023-03-01',)\", solve(*('2023-03-01',)), 60)\ncheck(\"fixture 3: ('2024-01-01',)\", solve(*('2024-01-01',)), 1)\ncheck(\"fixture 4: ('2024-12-31',)\", solve(*('2024-12-31',)), 366)\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":"95b0e98c476206ef260d7d56aa35532dc97efca0ef4d2a54c61248f53dda8c98","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nimport calendar\nimport statistics\nimport itertools\nfrom fractions import Fraction\nfrom datetime import date, datetime, timedelta, timezone\nfrom decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR\n\nN = 1\nobservations = []\ndef solve(text):\n    return (date.fromisoformat(text).month-1)*30+date.fromisoformat(text).day\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck(\"fixture 1: ('2024-03-01',)\", solve(*('2024-03-01',)), 61)\ncheck(\"fixture 2: ('2023-03-01',)\", solve(*('2023-03-01',)), 60)\ncheck(\"fixture 3: ('2024-01-01',)\", solve(*('2024-01-01',)), 1)\ncheck(\"fixture 4: ('2024-12-31',)\", solve(*('2024-12-31',)), 366)\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":" 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":"xn-ordinal-day-of-year","generated_at":"2026-09-29T14:38:02.454555+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Small exact fixtures expose this error without platform timing, external services, or probabilistic observations. Calendar conventions results depend on the stated convention.","root_cause":"Month lengths are approximated by thirty days.","sha256":"f29cb42490633e0c43bc5dddfc58334e9d791fed69415e0b72dc0bc537b82697","title":"Ordinal day of year · 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":41.365,"exit_code":1,"observations":[{"actual":60,"check":"fixture 1: ('2024-03-01',)","expected":61,"passed":false},{"actual":59,"check":"fixture 2: ('2023-03-01',)","expected":60,"passed":false},{"actual":0,"check":"fixture 3: ('2024-01-01',)","expected":1,"passed":false},{"actual":365,"check":"fixture 4: ('2024-12-31',)","expected":366,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ('2024-03-01',)\", \"actual\": 60, \"expected\": 61, \"passed\": false}, {\"check\": \"fixture 2: ('2023-03-01',)\", \"actual\": 59, \"expected\": 60, \"passed\": false}, {\"check\": \"fixture 3: ('2024-01-01',)\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 4: ('2024-12-31',)\", \"actual\": 365, \"expected\": 366, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":116.437,"exit_code":1,"observations":[{"actual":61,"check":"fixture 1: ('2024-03-01',)","expected":61,"passed":true},{"actual":61,"check":"fixture 2: ('2023-03-01',)","expected":60,"passed":false},{"actual":1,"check":"fixture 3: ('2024-01-01',)","expected":1,"passed":true},{"actual":361,"check":"fixture 4: ('2024-12-31',)","expected":366,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ('2024-03-01',)\", \"actual\": 61, \"expected\": 61, \"passed\": true}, {\"check\": \"fixture 2: ('2023-03-01',)\", \"actual\": 61, \"expected\": 60, \"passed\": false}, {\"check\": \"fixture 3: ('2024-01-01',)\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 4: ('2024-12-31',)\", \"actual\": 361, \"expected\": 366, \"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."}}