vitepress/docs/reference/default-theme-last-updated.md

Last Updated

The update time of the last content will be displayed in the lower right corner of the page. To enable it, add lastUpdated options to your config.

Site-Level Config

export default {
  lastUpdated: true
}

Frontmatter Config

This can be disabled per-page using the lastUpdated option on frontmatter:

---
lastUpdated: false
---

Also refer Default Theme: Last Updated for more details. Any truthy value at theme-level will also enable the feature unless explicitly disabled at site or page level.