title: Cron expression for every 6 hours in a day
body: <p>What should be the cron expression to run a job at 6am, 12 noon, 6pm and 12 midnight everyday?
  I am using the following in AWS Cloudwatch rule. It is not accepting the cron expression - 0 */6 * * *
  Getting the following message - &quot;Parameter ScheduleExpression is not valid&quot;</p>