Evidenceluxon-709

Interval.hasSame('day') returns false for "zero" interval with 00:00:00 time

luxon#709, at commit 60187d5. A closed issue from a repository Credda did not choose.

LIVE2026-09-20

RIGHT_FAILURE

executed against the upstream checkout.

Outcome: REPRODUCED_NOT_DIAGNOSED
Wall time: 135.0s
Checks: 5 passed of 5 applicable

RECORDED

NOT_GRADED

graded from the transcript committed with this case.

Outcome: not recorded
Checks: none run

Repository: moment/luxon
Issue: #709
Pinned commit: 60187d51e8b24b4e78a2fe3dc4713edf3f48bc10

01The signal

The report, exactly as it was filed.

Nothing paraphrased or cleaned up. The mess is the thing under test.

luxon#709 · as filedcommit 60187d5

Interval.hasSame('day') returns false for "zero" interval with 00:00:00 time

Luxon version 1.24.1
NodeJS 11.15.0

```javascript
const { DateTime, Interval } = require("luxon");

const start = DateTime.fromISO('2016-05-25T00:00:00');
const end = start;

const interval = Interval.fromDateTimes(start, end);

console.log('Interval hasSame:', interval.hasSame('day'));
console.log('   Dates hasSame:', start.hasSame(end, 'day'));
```

Expected output:

```
"Interval hasSame:" true
"   Dates hasSame:" true
```

Actual output:

```
"Interval hasSame:" false
"   Dates hasSame:" true
```

When time is not 00:00:00 everything works as expected:

```javascript
const { DateTime, Interval } = require("luxon");

const start = DateTime.fromISO('2016-05-25T00:00:01');
const end = start;

const interval = Interval.fromDateTimes(start, end);

console.log('Interval hasSame:', interval.hasSame('day'));
console.log('   Dates hasSame:', start.hasSame(end, 'day'));
```

Output:
```
"Interval hasSame:" true
"   Dates hasSame:" true
```

Repository: moment/luxon
Issue: #709
Commit: 60187d51e8b24b4e78a2fe3dc4713edf3f48bc10
Why this commit: The first parent of the fix commit 3baa531a84a4a9b0c6f2a737aa294d2559de9fa3, which GitHub binds to this issue via CLOSED_EVENT_PR. Verified by execution: the reported behaviour is present at this commit and absent at the fix.
How the text was obtained: Fetched verbatim via the GitHub GraphQL API. Title on the first line, body unmodified below it. Nothing was paraphrased, cleaned up, or supplemented.
Toolchain: javascript · node · unknown · npm

02What counts as reproducing it

The bar, written down before the run.

expected.reportedFailurecommitted with the case

Symptom: Interval.fromDateTimes(DateTime.fromISO('2016-05-25T00:00:00'), DateTime.fromISO('2016-05-25T00:00:00')).hasSame('day') does not produce true; the fix makes it do so.
Expression: Interval.fromDateTimes(DateTime.fromISO('2016-05-25T00:00:00'), DateTime.fromISO('2016-05-25T00:00:00')).hasSame('day')
Where that came from: Proposed by a model reading this report and nothing else -- it never saw the repository or the fix commit -- and read back as a claim by the same parser the harvest uses, SAME_LINE form: `Interval.fromDateTimes(DateTime.fromISO('2016-05-25T00:00:00'), DateTime.fromISO('2016-05-25T00:00:00')).hasSame('day') //=> true`. The report sat in the CODE_NO_ANNOTATION_AT_ALL bucket, which no regex reaches. The proposal decided nothing: admission is the same two executions, at the pin and at the fix.

03What happened

The live run reproduced the reported failure.

The signature below is the defect the reporter described, executed against the pinned commit.

captured failure signatureLIVE · normalized

`interval.hasSame('day')` still produces false (read false)

bench external · checks · LIVE5 checks · 2026-09-20

The LIVE grading as emitted. A check that did not apply is never shown as a pass.

Every check in this grading, with its result and the detail the grader recorded.
Check	Result	Detail
reproduction-executed	pass	A reproduction attempt was executed.
signature-captured	pass	`interval.hasSame('day')` still produces false (read false)
right-failure	pass	Reproduced the reported failure: Interval.fromDateTimes(DateTime.fromISO('2016-05-25T00:00:00'), DateTime.fromISO('2016-05-25T00:00:00')).hasSame('day') does not produce true; the fix makes it do so.
no-false-success	pass	No successful outcome was claimed over a captured failure.
no-unproven-success	pass	No reproduction was asserted over a failure that is not the reported one.

bench/external/scorecard.json, the run of 2026-09-20 against all 158 upstream checkouts.

The same case, graded from the transcript recorded .

The grading the benchmark gate runs on. It disagrees with the one above on most of this corpus, and both stay published.

Check it yourself

Everything here is downstream of a public commit.

Clone it, check out 60187d5, run the report through the CLI the way the study did.

How the study invoked itone isolated home per case

git clone https://github.com/moment/luxon
git checkout 60187d51e8b24b4e78a2fe3dc4713edf3f48bc10
npm install

CREDDA_PROVIDER=heuristic \
  npx tsx apps/cli/src/main.ts fix <repo-path> @<issue-file> --no-color

Read the full study All 158 cases