Quick answer
lastmod must be in a valid date format.
Sitemap Invalid Date
lastmod must be in a valid date format. Invalid format causes parsers to ignore or fail.
Common causes
- Wrong date format.
- Locale-specific date.
How to fix
- Use YYYY-MM-DD or full ISO 8601.
- Validate date format.
FAQ
- Date format?
- ISO 8601.
- Example?
- 2024-01-15 or 2024-01-15T12:00:00Z.
Fix it now
Try in validator (prefill this example)