Last verified or updated timestamp reflects actual verification date

A dateModified field populated only at creation time and never updated tells Google and AI crawlers that your listings are perpetually fresh — regardless of whether the underlying data is years stale. The schema-org dateModified property is used by search engines to prioritize recrawl frequency and by users to assess trustworthiness. Directories with static creation-time timestamps signal data decay: a business that closed 18 months ago still appears current. When users or LLMs consume your structured data and discover the timestamps are lies, the directory's authority collapses. Data freshness is a core data-integrity guarantee for any directory product.

Set dateVerified and dateModified server-side whenever listing data is updated or verified — never accept these timestamps from the submitter. Write the timestamp in the same transaction as the update.

// In your listing verification handler (e.g., src/app/api/listings/[id]/verify/route.ts)
await db.listing.update({
  where: { id: listingId },
  data: {
    // ... verified field values
    dateVerified: new Date(),
    dateModified: new Date(),
  },
});

Include dateModified in the JSON-LD block as an ISO 8601 string: "dateModified": listing.dateModified.toISOString(). Also update dateModified on any owner-initiated edit to the listing's content fields.