The AMP plugin provides a way to filter out a schema property using amp_schemaorg_metadata filter.
you can use the following snippet in your custom plugin or themes function.php to remove dates ( published and modified )
add_filter( 'amp_schemaorg_metadata', function ( $metadata ) {
unset( $metadata['datePublished'] );
unset( $metadata['dateModified'] );
return $metadata;
} );
Please note that SEO plugin like Yoast SEO and themes can also add their version of the schema and can overwrite AMP schema.
If you still have difficulties finding a solution please share more details, with your site health information using this form to investigate further.
