Input and reference-frame workflow

Local civil time to UTC workflow

Resolve a wall-clock label into a reproducible instant without hiding timezone rules.

Required inputs

Local ISO date

Local clock time

IANA timezone identifier

Pinned tzdb release

Fold or gap evidence

Ordered execution

Work the protocol

  1. 1

    Validate the civil fields independently.

  2. 2

    Load the named timezone rules.

  3. 3

    Detect an ordinary time, fold, or gap.

  4. 4

    Require a documented fold choice or gap correction.

  5. 5

    Emit the offset and UTC instant together.

Outputs

  • UTC instant
  • Resolved offset
  • Timezone-rule provenance

Done only when

  • The conversion reproduces under the pinned tzdb.
  • The civil input remains attached.
  • Ambiguity is resolved or retained.

Fail closed

Refusal conditions

  • Only a current UTC offset is supplied.
  • A fold has two candidates and no policy.
  • A gap is silently shifted.