title: How to add hour to date
body: <p>I am trying to get the date with a variable year, month and day but an specific hour.</p>
  
  <p>Let me explain myself. I have a variable called <strong><em>$date</em></strong> using the next format</p>
  
  <pre><code>date=$(date +%Y%m%d)
  </code></pre>
  
  <p>Which gives me 20130814 (for today). Just as I want for that variable</p>
  
  <p>But I need another variable, let's call it <strong><em>$date1</em></strong> who will have something like <strong><em>$date</em></strong> but an specific hour. I mean, taking the example above, 2013081405. I need to add that <strong><em>05</em></strong> to <strong><em>$date</em></strong> every single day, that means that for tomorrow I will have 2013081505 and so on</p>