diff --git a/core/lib/Drupal/Core/Datetime/DrupalDateTime.php b/core/lib/Drupal/Core/Datetime/DrupalDateTime.php
index d5fdbe2..bd0a364 100644
--- a/core/lib/Drupal/Core/Datetime/DrupalDateTime.php
+++ b/core/lib/Drupal/Core/Datetime/DrupalDateTime.php
@@ -17,6 +17,25 @@
  * DrupalDateTime::createFromArray( array('year' => 2010, 'month' => 9, 'day' => 28) )
  *
  * @see \Drupal/Component/Datetime/DateTimePlus.php
+ *
+ * @param string $format
+ * @param string $time
+ *
+ * @method \DateTime add(\DateInterval $interval)
+ * @method static \DateTime createFromFormat($format, $time,  $timezone = NULL, $settings = [])
+ * @method static array getLastErrors()
+ * @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 $interval)
+ * @method \DateInterval diff($datetime2, $absolute = FALSE)
+ * @method int getOffset()
+ * @method int getTimestamp()
+ * @method \DateTimeZone getTimezone()
  */
 class DrupalDateTime extends DateTimePlus {