날짜 처리

• Date
  .getTime()
  .setTime()

Date date = new Date();
long time = date.getTime();
date.setTime(0);

• Calendar
  .YEAR
  .MONTH
  .DAY_OF_MONTH
  .DATE
  .LONG
  .SHORT
  .getInstance() // GregorianCalendar; 0 ~ 11
  .get()
  .getDisplayName()
  .add()

Calendar greCal = Calendar.getInstance();
int year = greCal.get(Calendar.YEAR);
int month = greCal.get(Calendar.MONTH);
int date = greCal.get(Calendar.DAY_OF_MONTH);
String monthKorea = greCal.getDisplayName(Calendar.MONTH, Calendar.LONG, Locale.KOREA);
String monthUS = greCal.getDisplayName(Calendar.MONTH, Calendar.SHORT, Locale.US);
Calendar calendar = new GregorianCalendar(2000, 11, 31);	// 2000/12/31
calendar.add(Calendar.DATE, 10);
calendar.add(Calendar.DATE, -10);
calendar.roll(Calendar.DATE, 10);