title: SOLR convert string to date
body: <p>I have a dynamic field in SOLR that its value is stores as string
  The value in it is a date string like:
   "md_LocalStartTime": "2013-01-31T22:12:54.8000000+0000",</p>
  
  <p>I want to get the max value for this 
  What wuery should I use to convert this to date and get the maximum?</p>
  
  <p>Thanks</p>