title: How to write update all based on row value for date type column?
body: <p>I have datetime column data type in <code>ReminderDetail</code> model, and I want to <code>update_all</code> values belonging to that column. I have written below query</p>
  
  <pre><code>ReminderDetail.update_all("reminder_date = date(reminder_date) - 1) 
  </code></pre>
  
  <p>but it updates like below:</p>
  
  <pre><code>Before 2013-07-05 06:37:00 
  After 2013-07-04 00:00:00
  </code></pre>
  
  <p>I want to update only the date, not hours. I want to like that 2013-07-04 06:37:00 or can I add some seconds to existing data ? can any one suggest ?</p>