title: Finding Max date in hive
body: <p>I have a column named "Date" which is in string datatype. 
  01-24-2018
  04-30-2017</p>
  
  <p>How to find the maximum of these dates which is in string?</p>
  
  <p>I used this query which is not returning the expected max.</p>
  
  <pre><code>max(to_date(from_unixtime(unix_timestamp(b.Date,'MM-dd-yyyy')))
  </code></pre>