How to fix non iso date on Squarespace

Steps for Squarespace

1. Squarespace generates structured data for Blog Posts and Products automatically using its built-in schema templates — date formatting is handled by the platform natively in most cases.
2. If you have injected custom JSON-LD via Settings → Advanced → Code Injection (site-wide header/footer) or via a page's Page Header Code Injection, review those scripts for any date fields.
3. In the Code Injection editor, locate any date strings and manually update them to ISO-8601 format: '2019-09-23' or '2019-09-23T00:00:00Z'.
4. If you use a third-party SEO extension (e.g. via Squarespace Extensions marketplace), check that extension's schema/structured data output settings.
5. For Blog posts specifically, the published date Squarespace uses in its auto-generated schema is pulled from the post's published date set in the Blog Post Editor — ensure this is set correctly (Squarespace handles the formatting itself).
6. Validate pages using Google's Rich Results Test after any code injection changes.

{
  "@context": "https://schema.org",
  "@type": "WebPage",
  "name": "My Product Page",
  "datePublished": "2019-09-23",
  "dateModified": "2024-03-15T09:30:00Z"
}

What is non iso date?

Structured data (the behind-the-scenes code that tells Google what your page is about) includes date fields like `datePublished` and `dateModified`. These dates must be written in a specific international format called ISO-8601 — which looks like `YYYY-MM-DD` (for example, `2019-09-23`) or with a full timestamp like `2019-09-23T00:00:00Z`. When dates are written in a casual format like "09/23/2019 00:00:00" or "September 23, 2019", search engines cannot reliably parse them and may ignore them entirely. Think of it like filling out an official form: the field has a required format, and anything else gets rejected.

Google uses `datePublished` and `dateModified` to understand content freshness — a key signal for ranking pages in news, article, product, and general search results. If Google can't parse your date, it may estimate the wrong publish date or show no date at all in search results, making your listings look outdated or untrustworthy compared to competitors whose dates are formatted correctly. For Answer Engine Optimization (AEO), freshness signals help your content surface in AI-generated answers and featured snippets, where recency is often a deciding factor. A malformed date can also cause your structured data to fail Google's Rich Results Test, disqualifying your pages from rich result enhancements like breadcrumb trails, review stars, and FAQ dropdowns — all of which directly impact click-through rates and organic traffic.

See the complete Non iso date guide for every platform and the full background.