getLastModified() публичный Метод

The returned date is configured to be in the GMT timezone.
public getLastModified ( ) : DateTime
Результат DateTime The last modification date or NULL
 /**
  * @test
  */
 public function setAndGetLastModifiedSetsTheLastModifiedHeader()
 {
     $date = \DateTime::createFromFormat(DATE_RFC2822, 'Tue, 22 May 2012 12:00:00 GMT');
     $fig = \DateTime::createFromFormat(DATE_RFC2822, 'Tue, 21 May 2012 12:00:00 GMT');
     $response = new Response();
     $response->setNow($date);
     $this->assertNull($response->getLastModified());
     $response->setLastModified($fig);
     $this->assertEquals($fig, $response->getLastModified());
 }