I whant to make a soft "evaluation for x days". After this x days the program should not start. To check the date every date the program starts it's stupid because anyone can roll back the time. My idea is to make an program that will work in background and at every 1 hour for example and will check if the time was not rolled back. The problem is: can I make a java program run in background? If not, can you give some other ideas for this "evaluation"? Thanks!