Exclude older content by date

I have a site with a lot of content and we have hit our limit, we don’t want it to be indexed if its older than say 1-2 years, i tried this code but got a critical error.

function wpswa_support_should_index_post( $should_index, $post ) {
	global $post;
	
	// Check if post date or modified date is older than 2 years, if yes, return false to prevent indexing.
	if (strtotime($post->post_date) < strtotime('-1 year') && strtorime($post->post_modified) < strtotime('-1 year')){
		return false;
	}

	// Otherwise return our original value
	return $should_index;
}
add_filter( 'algolia_should_index_post', 'wpswa_support_should_index_post', 10, 2 );
add_filter( 'algolia_should_index_searchable_post', 'wpswa_support_should_index_post', 10, 2 );