Gdn_Format::toDateTime PHP Method

    public static function toDateTime($Timestamp = '')
    {
        if ($Timestamp == '') {
            $Timestamp = time();
        }
        return date('Y-m-d H:i:s', $Timestamp);
    }

 /**
  * Grabs all new notifications and adds them to the sender's inform queue.
  *
  * This method gets called by dashboard's hooks file to display new
  * notifications on every pageload.
  *
  * @since 2.0.18
  * @access public
  *
  * @param Gdn_Controller $Sender The object calling this method.
  */
 public static function informNotifications($Sender)
 {
     $Session = Gdn::session();
     if (!$Session->isValid()) {
         return;
     }
     $ActivityModel = new ActivityModel();
     // Get five pending notifications.
     $Where = array('NotifyUserID' => Gdn::session()->UserID, 'Notified' => ActivityModel::SENT_PENDING);
     // If we're in the middle of a visit only get very recent notifications.
     $Where['DateUpdated >'] = Gdn_Format::toDateTime(strtotime('-5 minutes'));
     $Activities = $ActivityModel->getWhere($Where, 0, 5)->resultArray();
     $ActivityIDs = array_column($Activities, 'ActivityID');
     $ActivityModel->setNotified($ActivityIDs);
     $Sender->EventArguments['Activities'] =& $Activities;
     $Sender->fireEvent('InformNotifications');
     foreach ($Activities as $Activity) {
         if ($Activity['Photo']) {
             $UserPhoto = anchor(img($Activity['Photo'], array('class' => 'ProfilePhotoMedium')), $Activity['Url'], 'Icon');
         } else {
             $UserPhoto = '';
         }
         $Excerpt = Gdn_Format::plainText($Activity['Story']);
         $ActivityClass = ' Activity-' . $Activity['ActivityType'];
         $Sender->informMessage($UserPhoto . Wrap($Activity['Headline'], 'div', array('class' => 'Title')) . Wrap($Excerpt, 'div', array('class' => 'Excerpt')), 'Dismissable AutoDismiss' . $ActivityClass . ($UserPhoto == '' ? '' : ' HasIcon'));
     }
 }