Automatic shutdown

Hi, 

VM automatic shutdown has unwanted behavior when more than one user is notified.

If more than one user requests a delay, the times are accumulated instead of setting the time at the maximum of the requests.

For example, if at 16pm a user requests 2 hours of delay and at 16:15pm another user requests two hours, the machine shuts down at 20pm when it should do so at 18:15pm. I think!

Thanks