title: How can I filter a dataset in Delphi on a TDateTime field
body: <p>I have a dataset that I need to filter by time.  e.g. I want records where the time contained in a TDateTime field is between 6:00 AM and 6:00 PM.</p>
  
  <p>My dataset contains a field named time_of_day, of type TDateTime.  The value assigned to the filed is a time, with no date.  </p>
  
  <p>I have tried creating the filter string using both the string representation of the time (<code>time_of_day &gt;= '6:00 AM' and time_of_day &lt;= '6:00 PM'</code>), and also using the floating point representation (<code>time_of_day &gt;= 0.25 and time_of_day &lt; 0.75</code>), but neither have worked.</p>
  
  <p>I need to know how to construct the filter string to assign to the TDataSet.Filter property.</p>