/** * Expects a timestamp and converts it to an ISO 8601 date in UTC as needed by Solr. * * Example date output format: 1995-12-31T23:59:59Z * The trailing "Z" designates UTC time and is mandatory * * @param array Array of values, an array because of multivalued fields * @return array Modified array of values */ public function process(array $values) { $results = array(); foreach ($values as $timestamp) { $results[] = Util::timestampToUtcIso($timestamp); } return $results; }