Reproducible CLDR Provenance for iCalendar Time-Zone Mappings
A directly merged iCalendar contribution that resolves the latest CLDR source revision, fetches generated mapping data from that exact commit, and records the SHA in the output to prevent provenance drift.
#1581
merged PR
4
maintainer approvals
15,984
tests passed
139
mapping entries
01 · Engineering problem
The failure mode
The generated Windows-to-IANA time-zone mapping did not expose the exact CLDR revision behind its data. Fetching moving-branch content without pinning the source could allow the recorded version and generated mapping to diverge.
02 · Technical response
What changed
- 01Resolved the newest commit touching windowsZones.xml through GitHub’s commits API.
- 02Fetched the XML from that immutable SHA rather than from a moving branch.
- 03Recorded the same SHA in the generated module’s version field and source URL.
- 04Added generator, generated-output, ASCII-date, and injection-safety regression coverage.
03 · Verified outcome
Evidence, not implication
- ✓Four maintainers approved the final revision before merge.
- ✓The generator produced 139 entries with one consistent source SHA across version and documentation.
- ✓15,984 tests passed with Ruff and Towncrier validation clean.
- ✓The pinned two-request workflow prevents version/data mismatch by construction.
04 · Public record
Source evidence
Independent engineering and open-source work by Patrick Ribbsaeter / Ribbsaeter Systems. References to maintainers, repositories, or companies identify the public technical context only. No employment, client, vendor, or partnership relationship is implied unless explicitly stated.