{"abstract":"A fixed ordinary-year length also excludes the current day incorrectly.","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. The input year is <=9998; count elapsed days until January 1 of the following year. Exact operational definition: (date(date.fromisoformat(text).year+1,1,1)-date.fromisoformat(text)).days","contract_signature":"text","evaluation_group":"model-2a728a5f5ad330ce","failed_approach":"A constant leap-year assumption fails in ordinary years.","family":"xn-days-until-next-year-exclusive","id":"FA-6491","implementations":{"attempt":{"sha256":"944edd5af23902cf5646baa9286edc7e141f654e6266fde0ec6685ccbc5c41bf","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 366-date.fromisoformat(text).timetuple().tm_yday\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck(\"fixture 1: ('2024-12-31',)\", solve(*('2024-12-31',)), 1)\ncheck(\"fixture 2: ('2023-12-31',)\", solve(*('2023-12-31',)), 1)\ncheck(\"fixture 3: ('2024-01-01',)\", solve(*('2024-01-01',)), 366)\ncheck(\"fixture 4: ('2023-01-01',)\", solve(*('2023-01-01',)), 365)\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":"85ce487288dcc10508c6200eb7eff34bc8cf0f67d991db743eaf04916601665a","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 365-date.fromisoformat(text).timetuple().tm_yday\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck(\"fixture 1: ('2024-12-31',)\", solve(*('2024-12-31',)), 1)\ncheck(\"fixture 2: ('2023-12-31',)\", solve(*('2023-12-31',)), 1)\ncheck(\"fixture 3: ('2024-01-01',)\", solve(*('2024-01-01',)), 366)\ncheck(\"fixture 4: ('2023-01-01',)\", solve(*('2023-01-01',)), 365)\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-days-until-next-year-exclusive","generated_at":"2026-09-29T14:38:02.458711+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":"A fixed ordinary-year length also excludes the current day incorrectly.","sha256":"3d4125ef02c19446e8f1c7af6e56fee02c513f90b14d181f4ab96fb65f5d92b5","title":"Days until next year exclusive · 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":42.428,"exit_code":1,"observations":[{"actual":0,"check":"fixture 1: ('2024-12-31',)","expected":1,"passed":false},{"actual":1,"check":"fixture 2: ('2023-12-31',)","expected":1,"passed":true},{"actual":365,"check":"fixture 3: ('2024-01-01',)","expected":366,"passed":false},{"actual":365,"check":"fixture 4: ('2023-01-01',)","expected":365,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ('2024-12-31',)\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 2: ('2023-12-31',)\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 3: ('2024-01-01',)\", \"actual\": 365, \"expected\": 366, \"passed\": false}, {\"check\": \"fixture 4: ('2023-01-01',)\", \"actual\": 365, \"expected\": 365, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":116.002,"exit_code":1,"observations":[{"actual":-1,"check":"fixture 1: ('2024-12-31',)","expected":1,"passed":false},{"actual":0,"check":"fixture 2: ('2023-12-31',)","expected":1,"passed":false},{"actual":364,"check":"fixture 3: ('2024-01-01',)","expected":366,"passed":false},{"actual":364,"check":"fixture 4: ('2023-01-01',)","expected":365,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ('2024-12-31',)\", \"actual\": -1, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 2: ('2023-12-31',)\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 3: ('2024-01-01',)\", \"actual\": 364, \"expected\": 366, \"passed\": false}, {\"check\": \"fixture 4: ('2023-01-01',)\", \"actual\": 364, \"expected\": 365, \"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."}}