[Zaafir]: can i get a link or the code to change a user input time format to milliseconds
Milliseconds since... what? The standard choice in Java
(inherited from the Unix world) is to measure milliseconds since Jan 1, 1970 GMT. This is used in the java.util.Date class and associated classes like the evil Calendar and GregorianCalendar classes. Also less evil (less needlessly obfuscated) classes, like SimpleDateFormat. The last is probably what you want for parsing user input and converting it to a Date. For example:
As for how to get your code to execute for an hour... well, that depends. Does your code normally complete in less than an hour, and you're just looping repeatedly to keep it alive? Or does your code sometimes take more than an hour to complete its basic tasks, and you need to be able to kill it if it runs too long?