Calendar c = Calendar.getInstance();
c.add(Calendar.DATE,-3);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String now = sdf.format(c.getTime());
System.out.println(now);
Calendar c = Calendar.getInstance();
c.add(Calendar.DATE,-3);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String now = sdf.format(c.getTime());
System.out.println(now);