title: Grep messages for the last hour
body: <p>I have an application which emits logs in this format:</p>
  
  <pre><code>00:00:10,799 ERROR [stderr] (http-prfilrjb08/10.1.29.34:8180-9)     {}:return code:  500
  </code></pre>
  
  <p>I would need to monitor for new ERRORs in the log file, happened in the last hour. Looking at some tutorials I've come up with the following grep:</p>
  
  <pre><code> grep "^$(date -d -1 hour +'%H:%M:%S')" /space/log/server.log  | grep 'ERROR'
  </code></pre>
  
  <p>However nothing is grepped! Can you help me to fix it ?
  Thanks!</p>