title: Python datetime.now() with timezone
body: <p>I have a timezone which is float (for example 4.0).<br>
  I want to construct <code>datetime</code> with given timezone.</p>
  
  <p>I tried this,</p>
  
  <pre><code>datetime.now(timezone)
  </code></pre>
  
  <p>but it throws </p>
  
  <pre><code>TypeError: tzinfo argument must be None or of a tzinfo subclass, not type 'float'
  </code></pre>
  
  <p>So I wonder how can I make <code>tzinfo</code> from float?</p>