Layover Connection Time Checker mechanism

Model scope

The arithmetic and inclusive comparison are valid, but the instrument is not ready for a PASS verdict because its lookup-table schema and source/version requirements are underspecified. Retain the honest label that MCT changes and varies by airline and airport, and require users to verify the current value with the operating airline before booking.

• The comparison layover_minutes >= MCT_minutes is correct only when the MCT table row exactly matches the connecting airport, terminal pair, travel-flow categories, airline or operating-carrier rules, and ticket/baggage conditions.
• Layover duration must be explicitly computed as departure timestamp minus arrival timestamp after converting both timestamps to a common time basis; the specification does not define timezone or date-rollover handling.
• Buffer time is correctly defined as layover_minutes - MCT_minutes, but the specification does not explicitly state whether a zero buffer passes.
• MCT is generally an airline or airport operational minimum, not a universal recommended safety margin. The label should distinguish MCT from a traveler-recommended buffer.
• The stated table key of airport pair/terminal is incomplete: MCT can also depend on operating and marketing carrier, domestic/Schengen/international classification, passenger and baggage handling, immigration or security requirements, separate-ticket status, and terminal transfer method.

Units and conventions

• All computed durations are in integer minutes.
• Input timestamps are interpreted as ISO 8601 timestamps with explicit UTC offsets; timestamps must be normalized to UTC before subtraction.
• A departure on the following calendar day is allowed and must be represented by its date, not inferred only from clock time.
• MCT table values are in minutes.
• The comparison is inclusive: layover_minutes equal to MCT_minutes passes and produces a zero-minute buffer.
• The supplied MCT rows are dated test fixtures, not guarantees of current airline or airport policy.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "connecting_airport": "LHR",
    "arrival_timestamp": "2025-06-14T10:00:00Z",
    "departure_timestamp": "2025-06-14T11:30:00Z",
    "arrival_flow": "domestic",
    "departure_flow": "international",
    "arrival_terminal": "T2",
    "departure_terminal": "T5"
  },
  "expected_outputs": {
    "layover_minutes": 90,
    "mct_minutes": 90,
    "buffer_minutes": 0,
    "meets_mct": true
  },
  "reference_data": {
    "mct_row": {
      "airport": "LHR",
      "arrival_flow": "domestic",
      "departure_flow": "international",
      "arrival_terminal": "T2",
      "departure_terminal": "T5",
      "mct_minutes": 90
    },
    "source_convention": "widely tabulated standard value for common published MCT test fixtures; airport/airline dated guidance must be verified"
  },
  "working": "Both timestamps are already UTC. Layover = 11:30 - 10:00 = 1 hour 30 minutes = (1 x 60) + 30 = 90 minutes. Buffer = 90 - 90 = 0 minutes. Since 90 >= 90, the connection passes."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The checker is vulnerable to two specification hazards: an overnight connection can change from a valid 45-minute connection to an invalid negative duration if date-rollover conventions are interpreted differently, and excessively large timestamp values can lose one minute through unsafe integer precision. It also cannot produce authoritative results without a dated, airline- and airport-specific MCT table.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json
• BOUNDARY_HAZARD_CATALOG.json