title: Rails: time_select helper validation on previous given time?
body: <p>I would like to know if there is a built-in functionality of rails <code>time_select</code>, that handles the valid range of my end_time.</p>
  
  <p>I have <code>start_time</code> and <code>end_time</code>. <code>end_time</code> is not allowed to be "smaller" than <code>start_time</code>.</p>
  
  <pre><code>&lt;%= f.time_select :start_time, {minute_step: 15}%&gt;
  </code></pre>
  
  <p>How can I realize this? </p>
  
  <p>Thank you for help.</p>