diff --git a/core/lib/Drupal/Component/Datetime/DateTimePlus.php b/core/lib/Drupal/Component/Datetime/DateTimePlus.php
index 2e9bc02..5a8365c 100644
--- a/core/lib/Drupal/Component/Datetime/DateTimePlus.php
+++ b/core/lib/Drupal/Component/Datetime/DateTimePlus.php
@@ -23,6 +23,19 @@
  * errors are. This is less disruptive than allowing datetime exceptions
  * to abort processing. The calling script can decide what to do about
  * errors using hasErrors() and getErrors().
+ *
+ * @method $this add(\DateInterval $interval)
+ * @method static array getLastErrors()
+ * @method $this modify(string $modify)
+ * @method $this setDate(int $year, int $month, int $day)
+ * @method $this setISODate(int $year, int $week, int $day = 1)
+ * @method $this setTime(int $hour, int $minute, int $second = 0, int $microseconds = 0)
+ * @method $this setTimestamp(int $unixtimestamp)
+ * @method $this setTimezone(\DateTimeZone $timezone)
+ * @method $this sub(\DateInterval $interval)
+ * @method int getOffset()
+ * @method int getTimestamp()
+ * @method \DateTimeZone getTimezone()
  */
 class DateTimePlus {