I am trying to build an Oracle application with time-sensitive data. Since this is a demo system and the data set only works correctly if the system time is set to certain date, I am trying to figure out what the effects on Oracle are if I keep rolling back system clock to a certain date without stopping Oracle/reboot the system. For one thing, I know if the tables were created after the date I roll back to, export will complain because the tables should not exist yet.

As an example why I need to roll back the system clock: when user clicks on 'quarter to date' button in my page, it should show the data since the beginning of this current quarter. If I don't put in new data, as time goes by, the 'quarter to date' will not return anything after the next quarter starts. Thus I need to roll back the system clock in order to show some results.

Does anybody know any other effects when system clock got rolled back?

Any inputs are appreciated!