title: jQuery Datatables: Sort on one column when clicking on another.
body: <p>I have a jQuery datatable with date and time columns: </p>
  
  <pre><code>Date        Time        Note
  1/2/2015    10:02:03    Test
  1/4/2915    02:12:32    Test
  1/3/2015    02:05:03    Test
  3/2/2015    11:02:03    Test
  1/4/2015    01:02:13    Test
  </code></pre>
  
  <p>I want to implement a sort for time. When sorting on time, we first need to sort on date, then time:</p>
  
  <pre><code>Date        Time        Note
  1/2/2015    10:02:03    Test
  1/3/2015    02:05:03    Test
  1/4/2015    01:02:13    Test
  1/4/2915    02:12:32    Test
  3/2/2015    11:02:03    Test
  </code></pre>
  
  <p>I have the following code:</p>
  
  <pre><code>//jQuery datatable code
  { mData: 'date', sTitle: 'Date', sClass: "dtDate" },
  { mData: 'time', sTitle: 'Time', sClass: "dtTime", sType: "time-date-sort"},
  { mData: 'notes', sTitle: 'Notes' },
  // More code...
  
  jQuery.fn.dataTableExt.oSort['time-date-sort-asc'] = function(startTime, endTime) {      
      //Date and time sorts go here
      return sortedVal;
  };
  
  jQuery.fn.dataTableExt.oSort['time-date-sort-desc'] = function (startTime, endTime) {
      //Date and time sorts go here
      return sortedVal;
  };
  </code></pre>
  
  <p>I am able to sort on the time using this, but how would I first sort on date? <strong>I am trying to figure out how to get a reference of the date value in the table row (associated with the time value in that row).</strong> For example, <strong>how to I grab the date object <code>1/2/2015</code> for the row where time is <code>10:02:03</code>?</strong> It does not appear as if I can add custom parameters to the oSort function. Do I use <code>jQuery.fn.dataTableExt.oSort</code> or is <code>jQuery.fn.dataTableExt.afnSortData</code> a better option for this? </p>