FAILURE MAP
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FA-93136 / EV charging session scheduling / Open access

Weekly recurring charging windows: previous weekday wrap · case 01

Overnight windows continue into the wrong morning.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The after-midnight tail is looked up on the following weekday instead of the preceding one.

VERIFIED REPAIR

Use (day - 1) % 7 as the start day of the tail.

Unsuccessful approach: Clamping at Monday instead of wrapping breaks Sunday night windows.

Case contract

rules are [day_mask, start, end] with bit 0 = Monday .. bit 6 = Sunday. start < end is a same-day window [start, end); start == end means the whole selected day; start > end crosses midnight and belongs to its start day (Sunday continues into Monday). Return the sorted indices of rules allowing charging at (day 0..6, minute 0..1439).

Why this case matters

Depot, workplace and public EV chargers schedule sessions against prices, circuit limits and departure deadlines; a wrong decision silently strands a driver or overloads a feeder.

1 / The failure

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

N = 1
observations = []
def solve(rules, day, minute):
    hits = []
    for i, (mask, s, e) in enumerate(rules):
        today = mask >> day & 1
        yday = mask >> (day + 1) % 7 & 1
        if s == e:
            if today:
                hits.append(i)
        elif s < e:
            if today and s <= minute < e:
                hits.append(i)
        elif (today and minute >= s) or (yday and minute < e):
            hits.append(i)
    return hits
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[50, 1080, 60], [92, 0, 420], [118, 1080, 1320]], 0, 30],
   []],
  ['regression: previous weekday wrap (partial repair)',
   [[[72, 0, 1380], [114, 1380, 1080], [82, 1320, 60], [68, 1080, 1380]], 0, 900], [1]],
  ['control 1', [[[75, 1380, 360]], 0, 1379], []],
  ['control 2', [[[26, 1380, 420], [118, 360, 0], [104, 1080, 1080]], 3, 0], [2]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap',
   [[[18, 60, 0], [118, 1080, 0], [124, 60, 360], [93, 1080, 60]], 4, 0], [3]],
  ['regression: previous weekday wrap (partial repair)', [[[19, 1380, 1080]], 0, 61], []],
  ['control 1', [[[28, 1320, 1080], [123, 420, 1380], [9, 1380, 0]], 6, 359], []],
  ['control 2', [[[98, 1080, 0], [121, 1380, 360], [62, 360, 0], [52, 1080, 0]], 2, 1079], [2]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[4, 1380, 1320], [39, 0, 420], [94, 60, 1380]], 1, 900],
   [2]],
  ['regression: previous weekday wrap (partial repair)',
   [[[67, 1380, 420], [25, 60, 0], [87, 1320, 360], [82, 1320, 420]], 0, 359], [0, 1, 2, 3]],
  ['control 1', [[[103, 0, 360], [65, 360, 1380], [37, 1080, 1080]], 4, 60], []],
  ['control 2', [[[52, 420, 1320], [97, 1080, 360]], 0, 0], [1]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[124, 0, 0], [53, 1320, 360], [89, 60, 60]], 4, 30],
   [0, 2]],
  ['regression: previous weekday wrap (partial repair)',
   [[[67, 1380, 420], [25, 60, 0], [87, 1320, 360], [82, 1320, 420]], 0, 359], [0, 1, 2, 3]],
  ['control 1', [[[105, 420, 360], [31, 1380, 1320], [47, 1080, 1320]], 4, 60], [0, 1]],
  ['control 2', [[[59, 360, 60], [45, 420, 60]], 5, 360], [0]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[51, 360, 1080], [116, 1320, 420]], 0, 60], [1]],
  ['regression: previous weekday wrap (partial repair)',
   [[[68, 1320, 360], [42, 360, 360], [95, 0, 360], [40, 1380, 60]], 0, 359], [0, 2]],
  ['control 1', [[[51, 360, 60], [78, 1080, 1080], [25, 1320, 360], [11, 360, 0]], 2, 1380], [1]],
  ['control 2', [[[16, 1380, 0]], 1, 360], []]]]
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
boundary: Monday morning after Sunday night window[][0]Failed
boundary: same-day window end minute[][]Passed
boundary: whole-day rule[0][0]Passed
regression: previous weekday wrap[0][]Failed
regression: previous weekday wrap (partial repair)[1][1]Passed
control 1[][]Passed
control 2[0, 2][2]Failed

SHA-256 / 6545f69c6db9ade329ff3d44f6519f9e748b447d2c007a0933a80b1924659f73

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(rules, day, minute):
    hits = []
    for i, (mask, s, e) in enumerate(rules):
        today = mask >> day & 1
        yday = mask >> max(day - 1, 0) & 1
        if s == e:
            if today:
                hits.append(i)
        elif s < e:
            if today and s <= minute < e:
                hits.append(i)
        elif (today and minute >= s) or (yday and minute < e):
            hits.append(i)
    return hits
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[50, 1080, 60], [92, 0, 420], [118, 1080, 1320]], 0, 30],
   []],
  ['regression: previous weekday wrap (partial repair)',
   [[[72, 0, 1380], [114, 1380, 1080], [82, 1320, 60], [68, 1080, 1380]], 0, 900], [1]],
  ['control 1', [[[75, 1380, 360]], 0, 1379], []],
  ['control 2', [[[26, 1380, 420], [118, 360, 0], [104, 1080, 1080]], 3, 0], [2]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap',
   [[[18, 60, 0], [118, 1080, 0], [124, 60, 360], [93, 1080, 60]], 4, 0], [3]],
  ['regression: previous weekday wrap (partial repair)', [[[19, 1380, 1080]], 0, 61], []],
  ['control 1', [[[28, 1320, 1080], [123, 420, 1380], [9, 1380, 0]], 6, 359], []],
  ['control 2', [[[98, 1080, 0], [121, 1380, 360], [62, 360, 0], [52, 1080, 0]], 2, 1079], [2]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[4, 1380, 1320], [39, 0, 420], [94, 60, 1380]], 1, 900],
   [2]],
  ['regression: previous weekday wrap (partial repair)',
   [[[67, 1380, 420], [25, 60, 0], [87, 1320, 360], [82, 1320, 420]], 0, 359], [0, 1, 2, 3]],
  ['control 1', [[[103, 0, 360], [65, 360, 1380], [37, 1080, 1080]], 4, 60], []],
  ['control 2', [[[52, 420, 1320], [97, 1080, 360]], 0, 0], [1]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[124, 0, 0], [53, 1320, 360], [89, 60, 60]], 4, 30],
   [0, 2]],
  ['regression: previous weekday wrap (partial repair)',
   [[[67, 1380, 420], [25, 60, 0], [87, 1320, 360], [82, 1320, 420]], 0, 359], [0, 1, 2, 3]],
  ['control 1', [[[105, 420, 360], [31, 1380, 1320], [47, 1080, 1320]], 4, 60], [0, 1]],
  ['control 2', [[[59, 360, 60], [45, 420, 60]], 5, 360], [0]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[51, 360, 1080], [116, 1320, 420]], 0, 60], [1]],
  ['regression: previous weekday wrap (partial repair)',
   [[[68, 1320, 360], [42, 360, 360], [95, 0, 360], [40, 1380, 60]], 0, 359], [0, 2]],
  ['control 1', [[[51, 360, 60], [78, 1080, 1080], [25, 1320, 360], [11, 360, 0]], 2, 1380], [1]],
  ['control 2', [[[16, 1380, 0]], 1, 360], []]]]
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
boundary: Monday morning after Sunday night window[][0]Failed
boundary: same-day window end minute[][]Passed
boundary: whole-day rule[0][0]Passed
regression: previous weekday wrap[][]Passed
regression: previous weekday wrap (partial repair)[][1]Failed
control 1[][]Passed
control 2[2][2]Passed

SHA-256 / d05fa09e9041f2d5c09d75d0701bae9d003128f70bc4c3c27d585c2f8e68420f

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(rules, day, minute):
    hits = []
    for i, (mask, s, e) in enumerate(rules):
        today = mask >> day & 1
        yday = mask >> (day - 1) % 7 & 1
        if s == e:
            if today:
                hits.append(i)
        elif s < e:
            if today and s <= minute < e:
                hits.append(i)
        elif (today and minute >= s) or (yday and minute < e):
            hits.append(i)
    return hits
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[50, 1080, 60], [92, 0, 420], [118, 1080, 1320]], 0, 30],
   []],
  ['regression: previous weekday wrap (partial repair)',
   [[[72, 0, 1380], [114, 1380, 1080], [82, 1320, 60], [68, 1080, 1380]], 0, 900], [1]],
  ['control 1', [[[75, 1380, 360]], 0, 1379], []],
  ['control 2', [[[26, 1380, 420], [118, 360, 0], [104, 1080, 1080]], 3, 0], [2]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap',
   [[[18, 60, 0], [118, 1080, 0], [124, 60, 360], [93, 1080, 60]], 4, 0], [3]],
  ['regression: previous weekday wrap (partial repair)', [[[19, 1380, 1080]], 0, 61], []],
  ['control 1', [[[28, 1320, 1080], [123, 420, 1380], [9, 1380, 0]], 6, 359], []],
  ['control 2', [[[98, 1080, 0], [121, 1380, 360], [62, 360, 0], [52, 1080, 0]], 2, 1079], [2]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[4, 1380, 1320], [39, 0, 420], [94, 60, 1380]], 1, 900],
   [2]],
  ['regression: previous weekday wrap (partial repair)',
   [[[67, 1380, 420], [25, 60, 0], [87, 1320, 360], [82, 1320, 420]], 0, 359], [0, 1, 2, 3]],
  ['control 1', [[[103, 0, 360], [65, 360, 1380], [37, 1080, 1080]], 4, 60], []],
  ['control 2', [[[52, 420, 1320], [97, 1080, 360]], 0, 0], [1]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[124, 0, 0], [53, 1320, 360], [89, 60, 60]], 4, 30],
   [0, 2]],
  ['regression: previous weekday wrap (partial repair)',
   [[[67, 1380, 420], [25, 60, 0], [87, 1320, 360], [82, 1320, 420]], 0, 359], [0, 1, 2, 3]],
  ['control 1', [[[105, 420, 360], [31, 1380, 1320], [47, 1080, 1320]], 4, 60], [0, 1]],
  ['control 2', [[[59, 360, 60], [45, 420, 60]], 5, 360], [0]]],
 [['boundary: Monday morning after Sunday night window', [[[64, 1320, 360]], 0, 100], [0]],
  ['boundary: same-day window end minute', [[[127, 60, 360]], 3, 360], []],
  ['boundary: whole-day rule', [[[4, 420, 420]], 2, 5], [0]],
  ['regression: previous weekday wrap', [[[51, 360, 1080], [116, 1320, 420]], 0, 60], [1]],
  ['regression: previous weekday wrap (partial repair)',
   [[[68, 1320, 360], [42, 360, 360], [95, 0, 360], [40, 1380, 60]], 0, 359], [0, 2]],
  ['control 1', [[[51, 360, 60], [78, 1080, 1080], [25, 1320, 360], [11, 360, 0]], 2, 1380], [1]],
  ['control 2', [[[16, 1380, 0]], 1, 360], []]]]
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
boundary: Monday morning after Sunday night window[0][0]Passed
boundary: same-day window end minute[][]Passed
boundary: whole-day rule[0][0]Passed
regression: previous weekday wrap[][]Passed
regression: previous weekday wrap (partial repair)[1][1]Passed
control 1[][]Passed
control 2[2][2]Passed

SHA-256 / baa1420dcaad1af9c2d5ff5e586d06312e7fb049554eef3090b112aa0b706a83

Verification & scope

Deterministic stipulated toy contract for teaching; no claim of conformance with any standard, vendor protocol or production controller. 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 2026-09-29T14:51:52.339220+00:00.

Case digest / df392efb70454eab603e96111b7102900b8a34721d080a787d678f9f47872579