public function process(array $values)
    {
        $results = [];
        $formatService = GeneralUtility::makeInstance(FormatService::class);

        foreach ($values as $timestamp) {
            $results[] = $formatService->timestampToUtcIso($timestamp);
        }

        return $results;
    }
public function process(array $values)
    {
        $results = [];
        $formatService = GeneralUtility::makeInstance(FormatService::class);

        foreach ($values as $timestamp) {
            $results[] = $formatService->timestampToUtcIso($timestamp);
        }

        return $results;
    }
public function process ( array $ values ) { $ results = [ ] ; $ formatService = GeneralUtility :: makeInstance ( FormatService :: class ) ; foreach ( $ values as $ timestamp ) { $ results [ ] = $ formatService -> timestampToUtcIso ( $ timestamp ) ; } return $ results ; }
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 $values Array of values, an array because of multivalued fields
@return array Modified array of values
Expects a timestamp and converts it to an ISO 8601 date in UTC as needed by Solr .