code: protected function hasToWait()
  	{
  		$return = true;
  
  		// Get the timestamp without seconds (see #5775)
  		$time = strtotime(date('Y-m-d H:i'));
  
  		// Lock the table
  		$this->Database->lockTables(array('tl_cron'=>'WRITE'));
  
  		// Get the last execution date
  		$objCron = $this->Database->prepare("SELECT * FROM tl_cron WHERE name='lastrun'")
  								  ->limit(1)
  								  ->execute();
  
  		// Add the cron entry
  		if ($objCron->numRows < 1)
  		{
  			$this->Database->query("INSERT INTO tl_cron (name, value) VALUES ('lastrun', $time)");
  			$return = false;
  		}
  
  		// Check the last execution time
  		elseif ($objCron->value <= ($time - $this->getCronTimeout()))
  		{
  			$this->Database->query("UPDATE tl_cron SET value=$time WHERE name='lastrun'");
  			$return = false;
  		}
  
  		$this->Database->unlockTables();
  
  		return $return;
  	}
docs: Check whether the last script execution was less than a minute ago
  
  @return boolean