title: How do I make Vertica timeseries, with slice_time '1 week', start on a specific day of week?
body: <p>I have select like this:</p>
  
  <pre><code>SELECT slice_time, TS_LAST_VALUE(x) FROM table \ 
   TIMESERIES slice_time as '1 week' OVER (partition by acc_id order by updated_at)
  </code></pre>
  
  <p>The problem I have is that my first "updated_at" is on 2013-02-20 (wednesday), but the timeseries query gives me first record on 2013-02-16 (saturday). I have noticed that for any date it produces the first record in the timeseries always on saturday before the actual date. </p>
  
  <p>Is there a way to make it start on a different day? </p>
  
  <p>Thanks.</p>