title: How to use WEEKNUM in big query?
body: <p>I am using Big Query SQL and I can't use a couple of functions and more specifically WEEKNUM. Everytime I try to, it outputs unrecognized function.</p>
  
  <p><a href="https://cloud.google.com/dataprep/docs/html/WEEKNUM-Function_118228789" rel="nofollow noreferrer">WEEKNUM</a></p>
  
  <p>During my search I found <a href="https://cloud.google.com/dataprep/docs/html/Derive-Transform_57344634#example---other-examples" rel="nofollow noreferrer">this</a> that I think it meansI can't use <code>derive</code> functions, and I also think that part of it is the WEEKNUM. I could be totally wrong though.</p>
  
  <p>So how can I use the WEEKNUM function or do what it does with another way?</p>
  
  <p>Thanks</p>