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FA-94031 / Shift rostering labor rules / Open access

Exactly-threshold night minutes not classified as a night shift · case 01

A shift with exactly three night hours is not treated as night work.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The night classification comparison is strict.

THE FAILURE

The night classification comparison is strict.

Unsuccessful approach: Multiplying the minute threshold by 60 treats it as hours and almost nothing qualifies.

Case contract

A shift [start, end] in absolute minutes (day 0 starts at minute 0) and a night-shift threshold. The night period runs 23:00 to 06:00 across midnight. Return [night minutes, whether night minutes reach the threshold].

Why this case matters

Night-work classification drives night-worker limits and premiums and must handle shifts that start after midnight.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(shift, threshold):
    s, e = shift
    night = 0
    for d in range(s // 1440 - 1, e // 1440 + 1):
        lo = d * 1440 + 1380
        hi = d * 1440 + 1800
        night += max(0, min(e, hi) - max(s, lo))
    return [night, night > threshold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: night shift threshold 1', [[1380, 1560], 180], [180, True]),
  ('regression variant: night shift threshold 2', [[3780, 4500], 240], [240, True]),
  ('partial repair guard 3', [[2760, 3480], 240], [420, True]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[3000, 3030], 120], [30, False]),
  ('normal control 7', [[3780, 4380], 120], [120, True]),
  ('normal control 8', [[8520, 8700], 180], [120, False])],
 [('regression: night shift threshold 1', [[8600, 8780], 180], [180, True]),
  ('regression variant: night shift threshold 2', [[2880, 3060], 180], [180, True]),
  ('partial repair guard 3', [[1440, 2253], 180], [360, True]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[360, 390], 180], [0, False]), ('normal control 7', [[7500, 8220], 120], [60, False]),
  ('normal control 8', [[4200, 4230], 180], [0, False])],
 [('regression: night shift threshold 1', [[3000, 3600], 240], [240, True]),
  ('partial repair guard 2', [[1320, 1911], 240], [420, True]),
  ('boundary control 3', [[1380, 1560], 180], [180, True]),
  ('boundary control 4', [[120, 480], 180], [240, True]),
  ('normal control 5', [[2340, 2670], 240], [0, False]),
  ('normal control 6', [[1260, 2159], 240], [420, True]),
  ('normal control 7', [[4320, 4920], 240], [360, True]),
  ('normal control 8', [[4200, 4230], 120], [0, False])],
 [('regression: night shift threshold 1', [[8600, 8840], 240], [240, True]),
  ('regression variant: night shift threshold 2', [[900, 1620], 240], [240, True]),
  ('partial repair guard 3', [[2820, 3540], 180], [420, True]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('boundary control 5', [[1380, 1559], 180], [179, False]),
  ('normal control 6', [[6060, 6300], 240], [60, False]),
  ('normal control 7', [[7020, 7260], 120], [120, True]),
  ('normal control 8', [[4102, 4282], 180], [22, False])],
 [('regression: night shift threshold 1', [[5820, 6000], 180], [180, True]),
  ('regression variant: night shift threshold 2', [[2700, 2940], 120], [120, True]),
  ('boundary control 3', [[1320, 1800], 180], [420, True]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('normal control 5', [[6180, 6256], 240], [0, False]),
  ('normal control 6', [[4200, 4230], 240], [0, False]),
  ('normal control 7', [[2700, 2880], 120], [60, False]),
  ('normal control 8', [[6060, 6300], 240], [60, False])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: night shift threshold 1[180, False][180, True]Failed
regression variant: night shift threshold 2[240, False][240, True]Failed
partial repair guard 3[420, True][420, True]Passed
boundary control 4[179, False][179, False]Passed
boundary control 5[420, True][420, True]Passed
normal control 6[30, False][30, False]Passed
normal control 7[120, False][120, True]Failed
normal control 8[120, False][120, False]Passed

SHA-256 / 494a2670c54f2ae6a0117f60be9d8bc3c288623bed96542e88eac85fc0e3f916

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(shift, threshold):
    s, e = shift
    night = 0
    for d in range(s // 1440 - 1, e // 1440 + 1):
        lo = d * 1440 + 1380
        hi = d * 1440 + 1800
        night += max(0, min(e, hi) - max(s, lo))
    return [night, night >= threshold * 60]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: night shift threshold 1', [[1380, 1560], 180], [180, True]),
  ('regression variant: night shift threshold 2', [[3780, 4500], 240], [240, True]),
  ('partial repair guard 3', [[2760, 3480], 240], [420, True]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[3000, 3030], 120], [30, False]),
  ('normal control 7', [[3780, 4380], 120], [120, True]),
  ('normal control 8', [[8520, 8700], 180], [120, False])],
 [('regression: night shift threshold 1', [[8600, 8780], 180], [180, True]),
  ('regression variant: night shift threshold 2', [[2880, 3060], 180], [180, True]),
  ('partial repair guard 3', [[1440, 2253], 180], [360, True]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[360, 390], 180], [0, False]), ('normal control 7', [[7500, 8220], 120], [60, False]),
  ('normal control 8', [[4200, 4230], 180], [0, False])],
 [('regression: night shift threshold 1', [[3000, 3600], 240], [240, True]),
  ('partial repair guard 2', [[1320, 1911], 240], [420, True]),
  ('boundary control 3', [[1380, 1560], 180], [180, True]),
  ('boundary control 4', [[120, 480], 180], [240, True]),
  ('normal control 5', [[2340, 2670], 240], [0, False]),
  ('normal control 6', [[1260, 2159], 240], [420, True]),
  ('normal control 7', [[4320, 4920], 240], [360, True]),
  ('normal control 8', [[4200, 4230], 120], [0, False])],
 [('regression: night shift threshold 1', [[8600, 8840], 240], [240, True]),
  ('regression variant: night shift threshold 2', [[900, 1620], 240], [240, True]),
  ('partial repair guard 3', [[2820, 3540], 180], [420, True]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('boundary control 5', [[1380, 1559], 180], [179, False]),
  ('normal control 6', [[6060, 6300], 240], [60, False]),
  ('normal control 7', [[7020, 7260], 120], [120, True]),
  ('normal control 8', [[4102, 4282], 180], [22, False])],
 [('regression: night shift threshold 1', [[5820, 6000], 180], [180, True]),
  ('regression variant: night shift threshold 2', [[2700, 2940], 120], [120, True]),
  ('boundary control 3', [[1320, 1800], 180], [420, True]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('normal control 5', [[6180, 6256], 240], [0, False]),
  ('normal control 6', [[4200, 4230], 240], [0, False]),
  ('normal control 7', [[2700, 2880], 120], [60, False]),
  ('normal control 8', [[6060, 6300], 240], [60, False])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: night shift threshold 1[180, False][180, True]Failed
regression variant: night shift threshold 2[240, False][240, True]Failed
partial repair guard 3[420, False][420, True]Failed
boundary control 4[179, False][179, False]Passed
boundary control 5[420, False][420, True]Failed
normal control 6[30, False][30, False]Passed
normal control 7[120, False][120, True]Failed
normal control 8[120, False][120, False]Passed

SHA-256 / ff6d4b2cc047ac212e957d7eca49ccf194d72c76b6d696b58baf9ca9495242e8

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

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Verification & scope

Stipulated toy labor rule for a bounded roster model; it is not legal advice and does not claim conformance with any jurisdiction, award, or collective agreement. 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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:52:00.632231+00:00.

Case digest / cfbfdb35e27fe4721a4370580e5607f4694f9524640fd819dcd4a4d4ae431ae7