title: Error inserting a timestamp with pg_query_params
body: <p>Im working in postgres 8.4 and PHP 5.4.3 using pg_query_params. I have a table called armies taht have 3 rows (well only for this example, it really have more). the id is an integer and the other two are timestamp withouth timezone. Now the SQL insert is: </p>
  
  <p>INSERT INTO public.armies(id,build_start,build_end) VALUES ($1,$2,$3) </p>
  
  <p>And the array I'm inserting is:</p>
  
  <pre><code>    $data['id'] = 1;
      $data['build_start'] = "now()";
      $data['build_end'] = "now() + time '00:00:50'";
  </code></pre>
  
  <p>The error is E_WARNING: pg_query_params(): Query failed: ERROR: invalid input syntax for type timestamp:  «now() + time '00:00:50'»</p>
  
  <p>Its works when i tried to insert it as a raw sql using pg_query like : INSERT INTO public.armies(id,build_start,build_end) VALUES (11935,now(),now() + time '00:00:50'). </p>
  
  <p>So I guess it has something to do with the pg_query_params(), I really really want to insert it using pg_query_params. </p>
  
  <p>What I want to achieve is sum that now() with that 00:00:50 seconds, so i can manage to alter that $data['build_end'].</p>