ADDITIONAL SYSTEM INFORMATION :
Windows 10, Java 64
the issue is reproducible on Java 7_u25 and java 8_221

A DESCRIPTION OF THE PROBLEM :
If you have a Calendar set to a specific timezone (e.g. "Europe/Budapest"), and you change its MILLISECOND field, the hour field will be incorrectly changed as well.

Work-around: performing a get on the HOUR field, before modifying the MILLISECOND filed will prevent the bug.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
TimeZone tz = TimeZone.getTimeZone("Europe/Budapest");
Calendar calendar = Calendar.getInstance();
// Work-around: uncomment this line to prevent the java Calendar bug
// System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
calendar.set(Calendar.MILLISECOND, 0);
System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Setting the MILLISECOND field won't change the HOUR field
ACTUAL -
Setting the MILLISECOND field changes the HOUR field

---------- BEGIN SOURCE ----------
import java.util.Calendar;
import java.util.TimeZone;

public class TestCalendar {

/**
* @param args
*/
public static void main(String[] args) {

TimeZone tz = TimeZone.getTimeZone("Europe/Budapest");
Calendar calendar = Calendar.getInstance();
// Work-around: uncomment this line to prevent the java Calendar bug
// System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
calendar.set(Calendar.MILLISECOND, 0);
System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
See source code commented out line

FREQUENCY : always