--- title: seo/json-ld-date-format · JSON-LD date format description: Date properties in JSON-LD should be ISO-8601. --- **Severity:** info ## What it checks Flags a value under a known date key (`datePublished`, `dateModified`, `startDate`, …) that is not ISO-8601. Reduced precision allowed by schema.org is accepted: year (`2026`), year-month (`2026-06`), full date, and date-time all pass. ## Why it matters Schema.org date properties expect ISO-8601; other formats may be ignored or misparsed. ## How to fix ```json "datePublished": "2026-06-26" ``` ## Mode differences **Source analysis** (the CLI, the dashboard's static baseline) composes each route's `` from `` in the page and its layout chain, followed into repo-local components, plus the known meta components (`svelte-meta-tags`, `svelte-seo`) and any you declare in `metaComponents`. It judges only a **literal** value; it never examines a dynamic one. **Rendered analysis** (the Vite plugin's build pass, a route you visit in the dashboard) reads the shipped ``, where every value is literal; the build pass covers prerendered routes only. When the two disagree, trust the rendered result. ## Disabling Record existing findings in the suppressions file (`npx svelte-vitals --update-suppressions`), scope the rule per route or path with `overrides`, or turn it off: ```js svelte-vitals.config.js export default { rules: { 'seo/json-ld-date-format': 'off' } }; ```