title: How to sync time on host wake-up within VirtualBox?
body: <p>I am running an Ubuntu 12.04-based box inside of Vagrant using VirtualBox. So far, everything is fine - except for one thing:</p>
  
  <p>Let's assume that the VM is running. Then, the host goes to standby-mode. After waking it up again, the VM is still running, but its internal clock continues where it stopped when the host went down. So this basically means: Put the host to sleep for 15 minutes, wake it up again, then the VM's internal clock is 15 minutes late.</p>
  
  <p>How can I fix this (setting the time manually is not an option for obvious reasons ;-))? Is there a way to run a script inside of a Vagrant VM whenever the host system changes its state?</p>
  
  <p>I've read in the <a href="http://www.virtualbox.org/manual/ch09.html#changetimesync">documentation</a> that by default the VirtualBox Guest Additions sync the time with the host every 10 seconds. Apparently this is not happening, but I can not find any place where it is disabled. So any ideas?</p>
  
  <p>PS: The Guest Additions are installed and match the version of VirtualBox being used.</p>