title: How to substract timestamp without timezone in PostgreSQL
body: <p>I'm currently using PostgreSQL 8.4 and need to substract from <code>now()</code> date on day. What I tried is <code>now() - 1</code> and it didn't work. Although <a href="http://www.postgresql.org/docs/9.2/static/functions-datetime.html" rel="nofollow">that page</a> said that we could use operator <code>-</code> to perform operations on date. More preciseli I recieved</p>
  
  <pre><code>ERROR:  operator does not exist: timestamp with time zone - integer
  </code></pre>
  
  <p>Any ideas?</p>