diff --git src/wp-includes/comment.php src/wp-includes/comment.php
index 6fcb4a6..e102675 100644
--- src/wp-includes/comment.php
+++ src/wp-includes/comment.php
@@ -2082,14 +2082,33 @@ function wp_get_current_commenter() {
 /**
  * Inserts a comment to the database.
  *
- * The available comment data key names are 'comment_author_IP', 'comment_date',
- * 'comment_date_gmt', 'comment_parent', 'comment_approved', and 'user_id'.
+ * You can set the comment date manually, by setting the values for 'comment_date'
+ * and 'comment_date_gmt' keys.
  *
  * @since 2.0.0
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
- * @param array $commentdata Contains information on the comment.
+ * @param array $commentdata {
+ *     Contains information on the comment.
+ *
+ *     @type string     $comment_agent         The browser's user agent string of the user who added the comment.
+ *                                             Default empty.
+ *     @type int|string $comment_approved      Whether the comment has been approved or trashed. Default 1.
+ *     @type string     $comment_author        The nickname of the user who added the comment. Default empty.
+ *     @type string     $comment_author_email  The email of the user who added the comment. Default empty.
+ *     @type string     $comment_author_IP     The IP address of the user who added the comment. Default empty.
+ *     @type string     $comment_author_url    The URL address of the comment author website. Default empty.
+ *     @type string     $comment_content       The comment content. Default empty.
+ *     @type string     $comment_date          The date of the comment. Default is the current time.
+ *     @type string     $comment_date_gmt      The date of the comment in the GMT timezone. Default is
+ *                                             the value of `$comment_date` in the GMT timezone.
+ *     @type int        $comment_karma         The comment karma. Default 0.
+ *     @type int        $comment_parent        Set this for the comment it belongs to, if any. Default 0.
+ *     @type int|string $comment_post_ID       The ID of the post the comment belongs to, if any. Default empty.
+ *     @type string     $comment_type          The comment type. Default empty.
+ *     @type int        $user_id               The ID of the user who added the comment. Default 0.
+ * }
  * @return int|bool The new comment's ID on success, false on failure.
  */
 function wp_insert_comment( $commentdata ) {