Source: https://guthlabs.ai/docs/instruments/circadian-phase-jet-lag-adjustment-estimator/
instrument / verified-clean
# Circadian Phase / Jet Lag Adjustment Estimator
The current ledger marks this instrument verified clean within the source-bound verification corpus.
Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**
## Inspectable records
[01**Overview**Purpose and lifecycle]()[02**Mechanism**Method and assumptions]()[03**Implementation**Binding and validation]()[04**Qualification**Evidence and errata]()
## Ledger state
The current ledger marks this instrument verified clean within the source-bound verification corpus.
**Area**: Biology, Medicine & Pharmacology (educational estimates only — every panel labeled not-medical-advice)
**Tranche**: tranche-5
**Evidence ID**: t5-206
**Ledger rows**: 1
No ledger note is attached.
## Review findings
The instrument should be marked FAIL until the westward formula is corrected to approximately timezone_shift*1.5, input constraints and rounding are specified, and the light-timing output is either formally defined with required inputs or removed. The existing rough population-average and not-medical-advice labels are appropriate but do not resolve the formula error or missing-output definition.
### Formula and scope findings
- The written westward formula, timezone_shift/1.5, is not the stated population heuristic of approximately 1.5 days per timezone; it should be timezone_shift*1.5. For eastward travel, division by 1.0 is numerically equivalent to multiplication by 1.0 but obscures the intended rate formulation.
- The formula does not define how direction is represented or validate that direction is eastward or westward.
- The claimed suggested light-exposure timing tips have no formula, timing inputs, or computation defined, so that output cannot be verified from this specification.
- A single timezone count and direction do not determine individualized light timing; travel schedule, destination time, chronotype, sleep timing, and prior light exposure are omitted.
### Unit assumptions
- timezone_shift is a nonnegative count of time zones crossed, dimensionless but conventionally measured in time-zone intervals.
- The intended heuristic is approximately 1.0 day per timezone eastward and 1.5 days per timezone westward.
- The written formula is evaluated literally in the written-formula test output; the corrected heuristic is shown separately for comparison.
- Direction must be an explicit categorical value such as "east" or "west".
- Estimated days are population-average educational estimates, not a clinical prediction.
## Boundary hardening
**BREAK_CLAIMED** · SELF_FLAGGED
The formula itself has no zero-denominator or function-domain failure, but the input convention is underspecified: treating westward travel as a negative timezone shift can produce a negative adjustment duration instead of the intended positive 2 days.
## Errata and corrections
No applied erratum is attached to this unique-name record.
## Inspectable example
4 review vectors are recorded. One source-bound sample is shown below.
````
{
"inputs": {
"timezone_shift": 3,
"direction": "east"
},
"expected_outputs": {
"estimated_adjustment_days_written_formula": 3,
"estimated_adjustment_days_corrected_heuristic": 3
},
"working": "Written formula: 3 / 1.0 = 3 days. Corrected heuristic: 3 * 1.0 = 3 days."
}
````
## Related workflows
No source-defined multi-instrument workflow membership is recorded.
## Sources and evidence
These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.
- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`
- `evidence-tranche5/tranche5-results.json`
- `BOUNDARY_HAZARD_CATALOG.json`