Mahmoud Hashemi marks the tenth anniversary of calendar versioning by tracing its origin on a payments infrastructure team and documenting widespread adoption. He explains that a colleague’s observation - using dates instead of semantic majors - launched calver.org and that organizations from Apple and NVIDIA to Home Assistant, pip, CockroachDB and yt-dlp now use date-based versioning. Apple’s 2025 jump to a single “26” across iOS, macOS, watchOS and visionOS is highlighted as a milestone, and several community migrations, a timeline of users, and near-adoption in language tooling (PEP 2026) demonstrate CalVer’s reach.
The 26.0 spec introduces concrete notation fixes and guidance: deprecating confusing doubled tokens (MM, DD) in favor of explicit forms (M for short month, 0M for zero-padded month) because many tools already relied on the old meanings; recommending unpadded YYYY.M.D as the sane default for libraries since SemVer and package tooling reject leading zeros; and endorsing padding when lexical sorting matters (filenames, image tags, container registries). Optional trailing segments are made explicit with brackets, badges remain compatible for now, and the site gains a changeloged spec (16.6, 19.7, 26.0), a FAQ, reorganized users page, case studies, and an invitation to continue discussion via issues.
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