test(format/date-time): add numeric offset without minutes as invalid

[vtushar06]

Following the methodology I used for ipv4 and uuid, I read RFC 3339 section 5.6 and found the suite has no date-time test for a numeric offset that omits the minutes.

RFC 3339 section 5.6 defines time-numoffset = ("+" / "-") time-hour ":" time-minute - the colon and the two-digit time-minute are both required. So +01 (hour only, no :mm) is invalid. The suite covers a bad offset minute (+10:60) and a bad offset hour (+24:00), but not a whole missing minutes component.

Changes

• Added 1 test case across draft3, draft4, draft6, draft7, draft2019-09, draft2020-12, and v1.
• 1985-04-12T23:20:50+01 - a numeric offset with no minutes - invalid.

Ecosystem Impact

1. ajv-formats 3.0.1 (full and fast): FAILS (accepts it). The offset in ajv's TIME regex is (z|([+-])(\d\d)(?::?(\d\d))?) - the entire (?::?(\d\d))? minute group is optional, so +01 matches with the minutes treated as absent. This is the default addFormats(ajv) mode.
2. python-jsonschema 4.25.1: PASSES (rejects it) - rfc3339-validator requires [+-]\d\d:\d\d.
3. sourcemeta/core is_rfc3339_datetime: PASSES (rejects it).
4. Corroboration: jsonschema-rs 0.45.0, boon 0.6.1, santhosh-tekuri/jsonschema v6.0.2, and @hyperjump/json-schema 1.17.6 all reject it - ajv-formats is the outlier.

This is the same regex-branch class as ajv-formats issue #117 (colonless offset +0130); the missing-minutes form +01 is the second, distinct sub-branch of the same optional group.

RFC References

• RFC 3339 section 5.6 (Internet Date/Time Format, time-numoffset): https://www.rfc-editor.org/rfc/rfc3339#section-5.6

Reproduction and the date-time cross-implementation matrix are in my evidence repo: https://github.com/vtushar06/JSON-Schema-format-test-Evidence/blob/main/date-time.md

Related: #965

[Copilot]

Pull request overview

Adds missing negative coverage for the date-time format by asserting that RFC 3339 numeric UTC offsets must include a minutes component (±HH:MM), and that an hour-only offset like +01 is invalid. This strengthens the test suite’s RFC 3339 conformance checks across supported drafts/versions.

Changes:

• Add a new invalid date-time test case for 1985-04-12T23:20:50+01 (offset missing :mm).
• Apply the same test addition consistently across draft3, draft4, draft6, draft7, draft2019-09, draft2020-12, and v1 test sets.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/v1/format/date-time.json	Adds invalid date-time case for numeric offset missing minutes.
tests/draft7/optional/format/date-time.json	Adds the same invalid offset-missing-minutes coverage for draft7 optional format tests.
tests/draft6/optional/format/date-time.json	Adds the same invalid offset-missing-minutes coverage for draft6 optional format tests.
tests/draft4/optional/format/date-time.json	Adds the same invalid offset-missing-minutes coverage for draft4 optional format tests.
tests/draft3/optional/format/date-time.json	Adds the same invalid offset-missing-minutes coverage for draft3 optional format tests.
tests/draft2020-12/optional/format/date-time.json	Adds the same invalid offset-missing-minutes coverage for draft2020-12 optional format tests.
tests/draft2019-09/optional/format/date-time.json	Adds the same invalid offset-missing-minutes coverage for draft2019-09 optional format tests.

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[jviotti]

Looks good and spec valid as far as I can tell!