title: Ubuntu timedatectl fails in Docker container
body: <p>I've got Ubuntu 16.04 LTS running in a Docker container (hosted on macOS). The date/time is off by about four days.</p>
  
  <pre><code>$ cat /etc/*-release
  DISTRIB_ID=Ubuntu
  DISTRIB_RELEASE=16.04
  DISTRIB_CODENAME=xenial
  DISTRIB_DESCRIPTION="Ubuntu 16.04.1 LTS"
  $ date
  Sun May  7 05:57:21 UTC 2017
  </code></pre>
  
  <p>Effective date is 11 May 2017 06:17:13 UTC.</p>
  
  <p>I wanted to fix this (checking <a href="https://help.ubuntu.com/lts/serverguide/NTP.html" rel="noreferrer">this</a> and <a href="https://www.digitalocean.com/community/tutorials/how-to-set-up-time-synchronization-on-ubuntu-16-04" rel="noreferrer">this</a>) but I can't even run <code>timedatectl</code>:</p>
  
  <pre><code>$ timedatectl status
  Failed to create bus connection: No such file or directory
  </code></pre>
  
  <p>How do I fix this?</p>