title: How to validate date and time in same variable using Codeigniter
body: <p>Users are able to choose a date and time in a custom pop-up box.</p>
  
  <p>It currently looks like this when users input the time and date:</p>
  
  <pre><code>DD.MM.YYY HH.MM
  </code></pre>
  
  <p>How can I validate this format in Codeigniter upon submitting, using the form validation library?</p>