FA-94026 / Shift rostering labor rules / Open access

Night overlap counted from window start even when the shift starts later · case 01

A shift starting at 01:00 is credited night minutes from 23:00.

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

ROOT CAUSE

The intersection start ignores the shift start.

VERIFIED REPAIR

Intersection starts at the later of shift start and window start.

Unsuccessful approach: Taking the earlier of the two starts overcounts the same way.

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) - lo)
    return [night, night >= threshold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: intersection start clip 1', [[120, 480], 180], [240, True]),
  ('regression variant: intersection start clip 2', [[3780, 4068], 120], [0, False]),
  ('partial repair guard 3', [[1800, 2400], 180], [0, False]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[3960, 4560], 120], [300, True]),
  ('normal control 7', [[20, 200], 240], [180, False]),
  ('normal control 8', [[360, 1160], 120], [0, False])],
 [('regression: intersection start clip 1', [[1320, 1800], 180], [420, True]),
  ('regression variant: intersection start clip 2', [[4200, 4380], 180], [120, False]),
  ('partial repair guard 3', [[4680, 5400], 180], [0, False]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[1010, 1040], 180], [0, False]),
  ('normal control 7', [[4200, 4920], 120], [420, True]),
  ('normal control 8', [[5880, 6360], 120], [240, True])],
 [('regression: intersection start clip 1', [[1380, 1560], 180], [180, True]),
  ('regression variant: intersection start clip 2', [[4200, 4230], 120], [0, False]),
  ('partial repair guard 3', [[1560, 2040], 120], [240, True]),
  ('boundary control 4', [[120, 480], 180], [240, True]),
  ('normal control 5', [[360, 1222], 180], [0, False]), ('normal control 6', [[3240, 3540], 120], [0, False]),
  ('normal control 7', [[4680, 4710], 180], [0, False]),
  ('normal control 8', [[2700, 3055], 180], [235, True])],
 [('regression: intersection start clip 1', [[1380, 1559], 180], [179, False]),
  ('regression variant: intersection start clip 2', [[8051, 8771], 180], [191, True]),
  ('partial repair guard 3', [[3000, 3600], 240], [240, True]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('normal control 5', [[3780, 4380], 180], [120, False]),
  ('normal control 6', [[3960, 4140], 240], [0, False]), ('normal control 7', [[414, 594], 240], [0, False]),
  ('normal control 8', [[3808, 3838], 240], [0, False])],
 [('regression: intersection start clip 1', [[900, 1410], 180], [30, False]),
  ('regression variant: intersection start clip 2', [[1400, 2000], 120], [400, True]),
  ('partial repair guard 3', [[2840, 3020], 240], [180, False]),
  ('boundary control 4', [[1320, 1800], 180], [420, True]),
  ('boundary control 5', [[1800, 2400], 180], [0, False]),
  ('normal control 6', [[4740, 4980], 180], [0, False]),
  ('normal control 7', [[1260, 2159], 240], [420, True]),
  ('normal control 8', [[7320, 8040], 180], [240, True])]]
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: intersection start clip 1	`[420, True]`	`[240, True]`	Failed
regression variant: intersection start clip 2	`[420, True]`	`[0, False]`	Failed
partial repair guard 3	`[420, True]`	`[0, False]`	Failed
boundary control 4	`[599, True]`	`[179, False]`	Failed
boundary control 5	`[840, True]`	`[420, True]`	Failed
normal control 6	`[720, True]`	`[300, True]`	Failed
normal control 7	`[260, True]`	`[180, False]`	Failed
normal control 8	`[420, True]`	`[0, False]`	Failed

SHA-256 / 05aa144924f8dd0f0b45d6975390b71cb7202883240864e4b8eea93a0383b76d

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) - min(s, lo))
    return [night, night >= threshold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: intersection start clip 1', [[120, 480], 180], [240, True]),
  ('regression variant: intersection start clip 2', [[3780, 4068], 120], [0, False]),
  ('partial repair guard 3', [[1800, 2400], 180], [0, False]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[3960, 4560], 120], [300, True]),
  ('normal control 7', [[20, 200], 240], [180, False]),
  ('normal control 8', [[360, 1160], 120], [0, False])],
 [('regression: intersection start clip 1', [[1320, 1800], 180], [420, True]),
  ('regression variant: intersection start clip 2', [[4200, 4380], 180], [120, False]),
  ('partial repair guard 3', [[4680, 5400], 180], [0, False]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[1010, 1040], 180], [0, False]),
  ('normal control 7', [[4200, 4920], 120], [420, True]),
  ('normal control 8', [[5880, 6360], 120], [240, True])],
 [('regression: intersection start clip 1', [[1380, 1560], 180], [180, True]),
  ('regression variant: intersection start clip 2', [[4200, 4230], 120], [0, False]),
  ('partial repair guard 3', [[1560, 2040], 120], [240, True]),
  ('boundary control 4', [[120, 480], 180], [240, True]),
  ('normal control 5', [[360, 1222], 180], [0, False]), ('normal control 6', [[3240, 3540], 120], [0, False]),
  ('normal control 7', [[4680, 4710], 180], [0, False]),
  ('normal control 8', [[2700, 3055], 180], [235, True])],
 [('regression: intersection start clip 1', [[1380, 1559], 180], [179, False]),
  ('regression variant: intersection start clip 2', [[8051, 8771], 180], [191, True]),
  ('partial repair guard 3', [[3000, 3600], 240], [240, True]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('normal control 5', [[3780, 4380], 180], [120, False]),
  ('normal control 6', [[3960, 4140], 240], [0, False]), ('normal control 7', [[414, 594], 240], [0, False]),
  ('normal control 8', [[3808, 3838], 240], [0, False])],
 [('regression: intersection start clip 1', [[900, 1410], 180], [30, False]),
  ('regression variant: intersection start clip 2', [[1400, 2000], 120], [400, True]),
  ('partial repair guard 3', [[2840, 3020], 240], [180, False]),
  ('boundary control 4', [[1320, 1800], 180], [420, True]),
  ('boundary control 5', [[1800, 2400], 180], [0, False]),
  ('normal control 6', [[4740, 4980], 180], [0, False]),
  ('normal control 7', [[1260, 2159], 240], [420, True]),
  ('normal control 8', [[7320, 8040], 180], [240, True])]]
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: intersection start clip 1	`[780, True]`	`[240, True]`	Failed
regression variant: intersection start clip 2	`[708, True]`	`[0, False]`	Failed
partial repair guard 3	`[1020, True]`	`[0, False]`	Failed
boundary control 4	`[778, True]`	`[179, False]`	Failed
boundary control 5	`[1380, True]`	`[420, True]`	Failed
normal control 6	`[1620, True]`	`[300, True]`	Failed
normal control 7	`[440, True]`	`[180, False]`	Failed
normal control 8	`[1220, True]`	`[0, False]`	Failed

SHA-256 / b0a9f18e7c821980c0d4b670488dc879b7f839105ceeba1053d10f8003399913

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: intersection start clip 1', [[120, 480], 180], [240, True]),
  ('regression variant: intersection start clip 2', [[3780, 4068], 120], [0, False]),
  ('partial repair guard 3', [[1800, 2400], 180], [0, False]),
  ('boundary control 4', [[1380, 1559], 180], [179, False]),
  ('boundary control 5', [[1320, 1800], 180], [420, True]),
  ('normal control 6', [[3960, 4560], 120], [300, True]),
  ('normal control 7', [[20, 200], 240], [180, False]),
  ('normal control 8', [[360, 1160], 120], [0, False])],
 [('regression: intersection start clip 1', [[1320, 1800], 180], [420, True]),
  ('regression variant: intersection start clip 2', [[4200, 4380], 180], [120, False]),
  ('partial repair guard 3', [[4680, 5400], 180], [0, False]),
  ('boundary control 4', [[1800, 2400], 180], [0, False]),
  ('boundary control 5', [[900, 1410], 180], [30, False]),
  ('normal control 6', [[1010, 1040], 180], [0, False]),
  ('normal control 7', [[4200, 4920], 120], [420, True]),
  ('normal control 8', [[5880, 6360], 120], [240, True])],
 [('regression: intersection start clip 1', [[1380, 1560], 180], [180, True]),
  ('regression variant: intersection start clip 2', [[4200, 4230], 120], [0, False]),
  ('partial repair guard 3', [[1560, 2040], 120], [240, True]),
  ('boundary control 4', [[120, 480], 180], [240, True]),
  ('normal control 5', [[360, 1222], 180], [0, False]), ('normal control 6', [[3240, 3540], 120], [0, False]),
  ('normal control 7', [[4680, 4710], 180], [0, False]),
  ('normal control 8', [[2700, 3055], 180], [235, True])],
 [('regression: intersection start clip 1', [[1380, 1559], 180], [179, False]),
  ('regression variant: intersection start clip 2', [[8051, 8771], 180], [191, True]),
  ('partial repair guard 3', [[3000, 3600], 240], [240, True]),
  ('boundary control 4', [[2940, 3300], 240], [300, True]),
  ('normal control 5', [[3780, 4380], 180], [120, False]),
  ('normal control 6', [[3960, 4140], 240], [0, False]), ('normal control 7', [[414, 594], 240], [0, False]),
  ('normal control 8', [[3808, 3838], 240], [0, False])],
 [('regression: intersection start clip 1', [[900, 1410], 180], [30, False]),
  ('regression variant: intersection start clip 2', [[1400, 2000], 120], [400, True]),
  ('partial repair guard 3', [[2840, 3020], 240], [180, False]),
  ('boundary control 4', [[1320, 1800], 180], [420, True]),
  ('boundary control 5', [[1800, 2400], 180], [0, False]),
  ('normal control 6', [[4740, 4980], 180], [0, False]),
  ('normal control 7', [[1260, 2159], 240], [420, True]),
  ('normal control 8', [[7320, 8040], 180], [240, True])]]
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: intersection start clip 1	`[240, True]`	`[240, True]`	Passed
regression variant: intersection start clip 2	`[0, False]`	`[0, False]`	Passed
partial repair guard 3	`[0, False]`	`[0, False]`	Passed
boundary control 4	`[179, False]`	`[179, False]`	Passed
boundary control 5	`[420, True]`	`[420, True]`	Passed
normal control 6	`[300, True]`	`[300, True]`	Passed
normal control 7	`[180, False]`	`[180, False]`	Passed
normal control 8	`[0, False]`	`[0, False]`	Passed

SHA-256 / 4166933d680e631201cc455bddeef1f8795e981b29207aae5e6ce01d37ea1004

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 2026-09-29T14:52:00.632911+00:00.

Case digest / b84a917c426633094f518e6ff19af81671bd26232a3bdbe4210c2fccc8cbea02