php – 更新Google日历 – 致命错误：调用未定义的函数dateTime(

PHP致命错误：在第45行的public_html / googleapi / calendarupdate.php中调用未定义的函数dateTime().它指的是：

$event->setStart.dateTime($startdatetime);

这是我当前的PHP代码错误：

<?php

header('Content-type: application/json');

require_once __DIR__ . '/google-api-php-client/src/Google/autoload.php';

$summary = $_POST["summary"];
$location = $_POST["location"];
$description = $_POST["description"];
$startdatetime = $_POST["startdatetime"];
$enddatetime = $_POST["enddatetime"];
$clientemail = $_POST["clientemail"];
$privatekey = $_POST["privatekey"];
$useremail = $_POST["useremail"];
$calendarid = $_POST["calendarid"];



$client_email = $clientemail;
$private_key = file_get_contents($privatekey);
$scopes = array('https://www.googleapis.com/auth/calendar');
$user_to_impersonate = $useremail;
$credentials = new Google_Auth_AssertionCredentials(
    $client_email,$scopes,$private_key,'notasecret',// Default P12 password
    'http://oauth.net/grant_type/jwt/1.0/bearer',// Default grant type
    $user_to_impersonate
);
$client = new Google_Client();
$client->setAssertionCredentials($credentials);
if ($client->getAuth()->isAccessTokenExpired()) {
  $client->getAuth()->refreshTokenWithAssertion();
}

$service = new Google_Service_Calendar($client);

$event = $service->events->get($useremail,$calendarid);
$event->setSummary($summary);
$event->setLocation($location);
$event->setStart.dateTime($startdatetime);
$event->setStart.timeZone('America/Los_Angeles');
$event->setEnd.dateTime($enddatetime);
$event->setEnd.timeZone('America/Los_Angeles');
$event->setDescription($description);

$updatedEvent = $service->events->update($useremail,$event->getId(),$event);

echo json_encode($updatedEvent);

我的PHP代码基于Google的API文档here.