title: Multiple -a with greater than / less than break bash script
body: <p>I wrote a bash script that performs a curl call only during business hours.  For some reason, the hourly comparison fails when I add an "-a" operator (and for some reason my bash does not recognize "&amp;&amp;").</p>
  
  <p>Though the script is much larger, here is the relevant piece:</p>
  
  <pre><code>HOUR=`date +%k`
  
  if [ $HOUR &gt; 7 -a $HOUR &lt; 17 ];
  then
    //do sync
  fi
  </code></pre>
  
  <p>The script gives me the error: </p>
  
  <pre><code>./tracksync: (last line): Cannot open (line number): No such file
  </code></pre>
  
  <p>However, this comparison does not fail:</p>
  
  <pre><code>if [ $DAY != "SUNDAY" -a $HOUR &gt; 7 ];
  then
    //do sync
  fi
  </code></pre>
  
  <p>Is my syntax wrong or is this a problem with my bash?</p>