FA-94011 / Shift rostering labor rules / Open access

Night window that began the previous evening is skipped · case 01

A shift starting at 02:00 earns no night minutes for its first four hours.

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

ROOT CAUSE

Night windows are enumerated from the shift start day, missing the window that opened at 23:00 the day before.

VERIFIED REPAIR

Start enumerating night windows one day before the shift start day.

Unsuccessful approach: Adding a window at the end instead of the start still misses the previous evening.

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, 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: previous evening window 1', [[120, 480], 180], [240, True]),
  ('regression variant: previous evening window 2', [[6060, 6300], 240], [60, False]),
  ('partial repair guard 3', [[7200, 7920], 240], [360, True]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[8100, 8820], 180], [240, True]),
  ('normal control 7', [[4680, 5160], 180], [0, False]),
  ('normal control 8', [[5640, 5703], 120], [3, False])],
 [('regression: previous evening window 1', [[2940, 3300], 240], [300, True]),
  ('regression variant: previous evening window 2', [[5760, 6500], 240], [360, True]),
  ('partial repair guard 3', [[4620, 4800], 180], [60, False]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[5720, 6440], 240], [400, True]),
  ('normal control 7', [[7080, 7560], 240], [420, True]),
  ('normal control 8', [[8460, 8940], 120], [360, True])],
 [('regression: previous evening window 1', [[4380, 4560], 120], [180, True]),
  ('regression variant: previous evening window 2', [[7200, 7920], 180], [360, True]),
  ('partial repair guard 3', [[328, 508], 180], [32, False]),
  ('boundary control 4', [[1380, 1560], 180], [180, True]),
  ('boundary control 5', [[120, 480], 180], [240, True]),
  ('normal control 6', [[3000, 3030], 120], [30, False]),
  ('normal control 7', [[3000, 3480], 240], [240, True]),
  ('normal control 8', [[5720, 6440], 120], [400, True])],
 [('regression: previous evening window 1', [[1560, 2040], 120], [240, True]),
  ('regression variant: previous evening window 2', [[60, 660], 120], [300, True]),
  ('partial repair guard 3', [[3000, 3030], 120], [30, False]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('boundary control 5', [[1380, 1559], 180], [179, False]),
  ('normal control 6', [[5700, 6300], 180], [420, True]),
  ('normal control 7', [[3180, 3360], 120], [60, False]),
  ('normal control 8', [[6060, 6780], 240], [60, False])],
 [('regression: previous evening window 1', [[3000, 3600], 240], [240, True]),
  ('regression variant: previous evening window 2', [[0, 203], 180], [203, True]),
  ('partial repair guard 3', [[1740, 2220], 240], [60, False]),
  ('boundary control 4', [[1320, 1800], 180], [420, True]),
  ('boundary control 5', [[1800, 2400], 180], [0, False]),
  ('normal control 6', [[4440, 4636], 180], [196, True]), ('normal control 7', [[420, 450], 180], [0, False]),
  ('normal control 8', [[6120, 6150], 120], [0, 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 fixture	Actual	Expected	Outcome
regression: previous evening window 1	`[0, False]`	`[240, True]`	Failed
regression variant: previous evening window 2	`[0, False]`	`[60, False]`	Failed
partial repair guard 3	`[0, False]`	`[360, True]`	Failed
boundary control 4	`[179, False]`	`[179, False]`	Passed
boundary control 5	`[420, True]`	`[420, True]`	Passed
normal control 6	`[240, True]`	`[240, True]`	Passed
normal control 7	`[0, False]`	`[0, False]`	Passed
normal control 8	`[3, False]`	`[3, False]`	Passed

SHA-256 / 9638cf5cd90d0016816baa935ec5d406c1040bce34dd4b5535a994093c7ada9f

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, e // 1440 + 2):
        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: previous evening window 1', [[120, 480], 180], [240, True]),
  ('regression variant: previous evening window 2', [[6060, 6300], 240], [60, False]),
  ('partial repair guard 3', [[7200, 7920], 240], [360, True]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[8100, 8820], 180], [240, True]),
  ('normal control 7', [[4680, 5160], 180], [0, False]),
  ('normal control 8', [[5640, 5703], 120], [3, False])],
 [('regression: previous evening window 1', [[2940, 3300], 240], [300, True]),
  ('regression variant: previous evening window 2', [[5760, 6500], 240], [360, True]),
  ('partial repair guard 3', [[4620, 4800], 180], [60, False]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[5720, 6440], 240], [400, True]),
  ('normal control 7', [[7080, 7560], 240], [420, True]),
  ('normal control 8', [[8460, 8940], 120], [360, True])],
 [('regression: previous evening window 1', [[4380, 4560], 120], [180, True]),
  ('regression variant: previous evening window 2', [[7200, 7920], 180], [360, True]),
  ('partial repair guard 3', [[328, 508], 180], [32, False]),
  ('boundary control 4', [[1380, 1560], 180], [180, True]),
  ('boundary control 5', [[120, 480], 180], [240, True]),
  ('normal control 6', [[3000, 3030], 120], [30, False]),
  ('normal control 7', [[3000, 3480], 240], [240, True]),
  ('normal control 8', [[5720, 6440], 120], [400, True])],
 [('regression: previous evening window 1', [[1560, 2040], 120], [240, True]),
  ('regression variant: previous evening window 2', [[60, 660], 120], [300, True]),
  ('partial repair guard 3', [[3000, 3030], 120], [30, False]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('boundary control 5', [[1380, 1559], 180], [179, False]),
  ('normal control 6', [[5700, 6300], 180], [420, True]),
  ('normal control 7', [[3180, 3360], 120], [60, False]),
  ('normal control 8', [[6060, 6780], 240], [60, False])],
 [('regression: previous evening window 1', [[3000, 3600], 240], [240, True]),
  ('regression variant: previous evening window 2', [[0, 203], 180], [203, True]),
  ('partial repair guard 3', [[1740, 2220], 240], [60, False]),
  ('boundary control 4', [[1320, 1800], 180], [420, True]),
  ('boundary control 5', [[1800, 2400], 180], [0, False]),
  ('normal control 6', [[4440, 4636], 180], [196, True]), ('normal control 7', [[420, 450], 180], [0, False]),
  ('normal control 8', [[6120, 6150], 120], [0, 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 fixture	Actual	Expected	Outcome
regression: previous evening window 1	`[0, False]`	`[240, True]`	Failed
regression variant: previous evening window 2	`[0, False]`	`[60, False]`	Failed
partial repair guard 3	`[0, False]`	`[360, True]`	Failed
boundary control 4	`[179, False]`	`[179, False]`	Passed
boundary control 5	`[420, True]`	`[420, True]`	Passed
normal control 6	`[240, True]`	`[240, True]`	Passed
normal control 7	`[0, False]`	`[0, False]`	Passed
normal control 8	`[3, False]`	`[3, False]`	Passed

SHA-256 / 10af7acb385aea5caf992aeb3d5acae98b7c745090076e9299901478f197871a

3 / The verified repair

Exit 0

"""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: previous evening window 1', [[120, 480], 180], [240, True]),
  ('regression variant: previous evening window 2', [[6060, 6300], 240], [60, False]),
  ('partial repair guard 3', [[7200, 7920], 240], [360, True]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[8100, 8820], 180], [240, True]),
  ('normal control 7', [[4680, 5160], 180], [0, False]),
  ('normal control 8', [[5640, 5703], 120], [3, False])],
 [('regression: previous evening window 1', [[2940, 3300], 240], [300, True]),
  ('regression variant: previous evening window 2', [[5760, 6500], 240], [360, True]),
  ('partial repair guard 3', [[4620, 4800], 180], [60, False]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[5720, 6440], 240], [400, True]),
  ('normal control 7', [[7080, 7560], 240], [420, True]),
  ('normal control 8', [[8460, 8940], 120], [360, True])],
 [('regression: previous evening window 1', [[4380, 4560], 120], [180, True]),
  ('regression variant: previous evening window 2', [[7200, 7920], 180], [360, True]),
  ('partial repair guard 3', [[328, 508], 180], [32, False]),
  ('boundary control 4', [[1380, 1560], 180], [180, True]),
  ('boundary control 5', [[120, 480], 180], [240, True]),
  ('normal control 6', [[3000, 3030], 120], [30, False]),
  ('normal control 7', [[3000, 3480], 240], [240, True]),
  ('normal control 8', [[5720, 6440], 120], [400, True])],
 [('regression: previous evening window 1', [[1560, 2040], 120], [240, True]),
  ('regression variant: previous evening window 2', [[60, 660], 120], [300, True]),
  ('partial repair guard 3', [[3000, 3030], 120], [30, False]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('boundary control 5', [[1380, 1559], 180], [179, False]),
  ('normal control 6', [[5700, 6300], 180], [420, True]),
  ('normal control 7', [[3180, 3360], 120], [60, False]),
  ('normal control 8', [[6060, 6780], 240], [60, False])],
 [('regression: previous evening window 1', [[3000, 3600], 240], [240, True]),
  ('regression variant: previous evening window 2', [[0, 203], 180], [203, True]),
  ('partial repair guard 3', [[1740, 2220], 240], [60, False]),
  ('boundary control 4', [[1320, 1800], 180], [420, True]),
  ('boundary control 5', [[1800, 2400], 180], [0, False]),
  ('normal control 6', [[4440, 4636], 180], [196, True]), ('normal control 7', [[420, 450], 180], [0, False]),
  ('normal control 8', [[6120, 6150], 120], [0, 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 fixture	Actual	Expected	Outcome
regression: previous evening window 1	`[240, True]`	`[240, True]`	Passed
regression variant: previous evening window 2	`[60, False]`	`[60, False]`	Passed
partial repair guard 3	`[360, True]`	`[360, True]`	Passed
boundary control 4	`[179, False]`	`[179, False]`	Passed
boundary control 5	`[420, True]`	`[420, True]`	Passed
normal control 6	`[240, True]`	`[240, True]`	Passed
normal control 7	`[0, False]`	`[0, False]`	Passed
normal control 8	`[3, False]`	`[3, False]`	Passed

SHA-256 / 56ca5d778837db13a1435e95498198e6dbffd014197285affb738559a4b442fe

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 2026-09-29T14:52:00.381395+00:00.

Case digest / 8b3c2757584d2269a0cae1fbe41a293a9623afc645846c7ad98c7af8b5212d89