|I don't think that is the goal.
If that is the goal then may I ask why do you want you application to suddenly stop working for every user. What purpose the purpose of this?
There is no suggestion I can give you for finding time, even if you assume that you want time in a particular time zone. As far as I know there is no way for a standalone computer to determine current time. In fact no device can have such capability because time is not absolute.