title: Replace a string with another string from a list depending on the value
body: <p>Let's say I have this string: <code>'2015/4/21 (Tuesday)'</code>. I want to replace 'Tuesday' with another string, for example: 'cat'. The result should be: <code>'2015/4/21 (cat)'</code>.</p>
  
  <p>But I also want it to be dynamic, if it's 'Tuesday', then 'cat'. If it's 'Monday', then it's dog, etc.</p>
  
  <p>How do I do this in PostgreSQL 8.4?</p>
  
  <p>There is a similar post: <a href="https://stackoverflow.com/questions/5060526/postgresql-replace-all-instances-of-a-string-within-text-field">postgresql - replace all instances of a string within text field</a></p>
  
  <p>But mine needs to replace something <em>dynamic</em> depending on the day and that post replaces a known value.</p>