diff --git a/core/lib/Drupal/Core/Datetime/DrupalDateTime.php b/core/lib/Drupal/Core/Datetime/DrupalDateTime.php
index d5fdbe22b9..a016ba6dcf 100644
--- a/core/lib/Drupal/Core/Datetime/DrupalDateTime.php
+++ b/core/lib/Drupal/Core/Datetime/DrupalDateTime.php
@@ -17,6 +17,23 @@
  * DrupalDateTime::createFromArray( array('year' => 2010, 'month' => 9, 'day' => 28) )
  *
  * @see \Drupal/Component/Datetime/DateTimePlus.php
+ *
+ * @method \DateTime add ( DateInterval $interval )
+ * @method static \DateTime createFromFormat ( string $format , string $time [, DateTimeZone $timezone ] )
+ * @method static array getLastErrors ( void )
+ * @method \DateTime modify ( string $modify )
+ * @method static \DateTime __set_state ( array $array )
+ * @method \DateTime setDate ( int $year , int $month , int $day )
+ * @method \DateTime setISODate ( int $year , int $week [, int $day = 1 ] )
+ * @method \DateTime setTime ( int $hour , int $minute [, int $second = 0 [, int $microseconds = 0 ]] )
+ * @method \DateTime setTimestamp ( int $unixtimestamp )
+ * @method \DateTime setTimezone ( DateTimeZone $timezone )
+ * @method \DateTime sub ( DateInterval $interval )
+ * @method \DateInterval diff ( DateTimeInterface $datetime2 [, bool $absolute = false ] )
+ * @method string format ( string $format )
+ * @method int getOffset ( void )
+ * @method int getTimestamp ( void )
+ * @method \DateTimeZone getTimezone ( void )
  */
 class DrupalDateTime extends DateTimePlus {