Whats wrong with this code segment

Here is a small code segment to simulate doing something periodically (say every 5 mins) in Java. Date class here is standard java.util.Date

Date currDate = new Date(); //sets currDate to current date
Date prevDate = currDate;
int interval = 5;

while (true) {
if (currDate.getTime() >= prevDate.getTime() + interval * 60 *1000){
doSomething();
prevDate = currDate;
}
currDate.setTime(currDate.getTime() + 1*60*1000) //increment by 1 minute
}



Will this work? If not why not. Ignore if I have made any compile errors. I am looking for a logical error or more of an error from programming language point of view.

Answer: It will not work because when you do prevDate = currDate its the reference that gets copied. So essentially prevDate and currDate always point to the same Date object. So there is never any time difference between the two. The correct way to do this would be
prevDate.setTime(currDate.getTime());
or
prevDate = currDate.clone();

I have made this error so many times in past few days that I should be kicking myself in the backside. Though in my case things were not abstracted out so nicely and were part of a larger code. This whole logic was split with assignment happening somewhere else, comparison happening somewhere else etc etc. So it was not so easy to track it. In Google I had used
Joda Time which provides much nicer interface and gives an immutable class. That would have saved me from this error because you cannot modify the JodaTime object. You would always have to create a new instance to increment it. So prevDate would have pointed to the older instance and the comparison would have gone through nicely.