title: Azure Timer Trigger: Cron expression for every hour on the hour
body: <p>Whats the cron expression for every hour on the hour?
  I tried this '0 0 * ? * *' but it threw an error
  I have a Azure function timer trigger</p>
  
  <p>This expression below runs every minute on the minute.</p>
  
  <pre><code>public static void Run([TimerTrigger("0 * * * * *")]TimerInfo myTimer, TraceWriter log)
  </code></pre>
  
  <p>Here is the error I received when I tried "0 0 * ? * * *" and "0 0 * ? * *"</p>
  
  <blockquote>
    <p>[11/22/2018 12:45:29 AM] A ScriptHost error has occurred
    [11/22/2018 12:45:29 AM] Microsoft.Azure.WebJobs.Host: Error indexing method 'Currencies.Run'. Microsoft.Azure.WebJobs.Extensions: The schedule expression '0 0 * ? * * *' was not recognized as a valid cron expression or timespan string.
    [11/22/2018 12:45:29 AM] Error indexing method 'Currencies.Run'
    [11/22/2018 12:45:29 AM] Microsoft.Azure.WebJobs.Host: Error indexing method 'Currencies.Run'. Microsoft.Azure.WebJobs.Extensions: The schedule expression '0 0 * ? * * *' was not recognized as a valid cron expression or timespan string.</p>
  </blockquote>