Integração Google Calendar

Fala pessoal, como estão?

Bom estou eu aqui para tirar uma dúvida e saber se alguém conseguiu resolver...

// Create a new entry using the calendar service's magic factory method
$event= $service->newEventEntry();

// Populate the event with the desired information
// Note that each attribute is crated as an instance of a matching class

$event->title = $service->newTitle("My Event");
$event->where = array($service->newWhere("Mountain View, California"));

$event->content =
$service->newContent(" This is my awesome event. RSVP required.");

// Set the date using RFC 3339 format.

$startDate = "2008-01-20";
$startTime = "14:00";
$endDate = "2008-01-20";
$endTime = "16:00";
$tzOffset = "-08";

$when = $service->newWhen();
$when->startTime = "{$startDate}T{$startTime}:00.000{$tzOffset}:00";
$when->endTime = "{$endDate}T{$endTime}:00.000{$tzOffset}:00";
$event->when = array($when);

// Upload the event to the calendar server
// A copy of the event as it is recorded on the server is returned
$newEvent = $service->insertEvent($event);

Na linha $event= $service->newEventEntry(); o Zend não ta conseguindo iniciar o método alguém sabe o problema?