---
title: "Structured data dates are invalid, lack a timezone, or modified < published (geo/jsonld-dates)"
description: "geo/jsonld-dates: Google asks for ISO 8601 dates with a timezone; ambiguous or inconsistent dates weaken freshness signals that Bing and AI engines use."
canonical: https://void-design.vercel.app/rules/geo/jsonld-dates
lastModified: 2026-09-16
---

# Structured data dates are invalid, lack a timezone, or modified < published

`geo/jsonld-dates` · severity **warn** · category AI search · detected by `void geo` and `void audit`

## Why it matters

Google asks for ISO 8601 dates with a timezone; ambiguous or inconsistent dates weaken freshness signals that Bing and AI engines use.

## How to fix it

Emit full ISO 8601 timestamps with a timezone (2026-09-01T09:00:00Z) and keep dateModified ≥ datePublished.

## References

- https://developers.google.com/search/docs/appearance/structured-data/article#structured-data-type-definitions

## More ai search rules

`void geo` reports 41 rules in this category. Generative-engine optimisation: whether AI crawlers that don't run JavaScript see the same content, valid and visible JSON-LD, an explicit AI robots policy, llms.txt, Markdown mirrors and answer-first writing.

- `home-entity-missing` Home page lacks Organization + a single WebSite node — [geo/home-entity-missing](https://void-design.vercel.app/rules/geo/home-entity-missing)
- `jsonld-schema` JSON-LD @context isn't schema.org or @type isn't a schema.org type — [geo/jsonld-schema](https://void-design.vercel.app/rules/geo/jsonld-schema)
- `jsonld-required` Structured data type is missing Google-required properties — [geo/jsonld-required](https://void-design.vercel.app/rules/geo/jsonld-required)
- `jsonld-recommended` Structured data missing recommended properties — [geo/jsonld-recommended](https://void-design.vercel.app/rules/geo/jsonld-recommended)
- `breadcrumb-invalid` BreadcrumbList positions, names or item URLs are invalid — [geo/breadcrumb-invalid](https://void-design.vercel.app/rules/geo/breadcrumb-invalid)
- `faq-deprecated` FAQPage/HowTo/SearchAction markup no longer produces rich results — [geo/faq-deprecated](https://void-design.vercel.app/rules/geo/faq-deprecated)
- `jsonld-id-unresolved` JSON-LD @id references don't resolve — [geo/jsonld-id-unresolved](https://void-design.vercel.app/rules/geo/jsonld-id-unresolved)
- `jsonld-not-visible` Structured data values don't appear on the page — [geo/jsonld-not-visible](https://void-design.vercel.app/rules/geo/jsonld-not-visible)

Detected by `void geo` and `void audit`. Explain it in a terminal: `void rules geo/jsonld-dates`