SimpleDateFormatter returns two different time zones

Question

I have these two strings as input strings

03/12/16
03/14/16

I make a single SimpleDateFormatter object to get the date difference like this

DateFormat formatter = new SimpleDateFormat("MM/dd/yy",Locale.US);
Date dateChkIn = formatter.parse("03/12/16");
System.out.println("Checkin date at nights check - "+dateChkIn.toString());
Date dateChkOut = formatter.parse("03/14/16");
System.out.println("Checkout date at nights check - "+dateChkOut.toString());
Long numberOfNghtsCalc = ((dateChkOut.getTime() - dateChkIn.getTime()) / 86400000L);
System.out.println("number of nigts calculated - "+ numberOfNghtsCalc);

Below is my output in the server

Checkin date at nights check - Sat Mar 12 00:00:00 EST 2016
Checkout date at nights check - Mon Mar 14 00:00:00 EDT 2016
number of nigts calculated - 1

Expected output is number of nigts calculated - 2 Please note the two different Time Zones which returned from the formatter

Update : 13-Mar-2016 is considered as DST changing date. Therefore my calculation is getting wrong. (divide by 86400000L)

Answer 1

I found the solution. I got to know that best solution would be use Joda Time. But with least change in the existing code, I think this tricky way will be better. Please edit this answer if you see any drawbacks.

    List<Date> dates = new ArrayList<Date>();
    Calendar calendar = new GregorianCalendar();
    calendar.setTime(dateChkIn);

    Date result = null;
    while (calendar.getTime().before(dateChkOut)){
            result = calendar.getTime();


            dates.add(result);
            calendar.add(Calendar.DATE, 1);
    }
    System.out.println("DAYS CALCULATED BY NEW SOLUTION: " + dates.size());
    newNumberOfNghtsCalc = (long) dates.size();
    dates.clear();

This has actually reduced the running time!

Time taken for code in Question : 275000 (in nano seconds)

Time taken for New solution: 103000