Input and reference-frame workflow

Timezone fold and gap triage

Branch repeated, nonexistent, and ordinary local times into explicit resolution paths.

Required inputs

Local timestamp

IANA zone

tzdb version

Source precision

Ordered execution

Work the protocol

  1. 1

    Resolve all candidate offsets.

  2. 2

    Classify zero candidates as a gap, two as a fold, and one as ordinary.

  3. 3

    For a fold retain both instants unless evidence selects one.

  4. 4

    For a gap require a source correction rather than runtime normalization.

  5. 5

    Run sensitivity across every retained instant.

Outputs

  • Temporal classification
  • Candidate-instant set
  • Sensitivity requirement

Done only when

  • All candidate instants are enumerated.
  • Selection evidence is attached.
  • Downstream consumers accept a set, not an assumed scalar.

Fail closed

Refusal conditions

  • The runtime default chooses a fold.
  • A gap is coerced without provenance.
  • Only the preferred chart is retained.