Java - getting consistent UTC values irrespective of server

Java - getting consistent UTC values irrespective of server

I am work on a version of a product which will be used by the users in
India and am working from India (GMT+5:30). Our Servers are in US. Some
scheme is to be applied which has a start date and end date (eg - From Aug
01, 00:00:00 to Aug 31 11:59:59 it must be active). Am using
http://www.ruddwire.com/handy-code/date-to-millisecond-calculators/ for I
used this code assuming getTime will have a consistent UTC time-
// dateStr is what user enters on UI like 1/08/2013 format = dd/MM/yyyy
public static long getUTCDateWithFormat(String dateStr, String format)
throws ParseException {
SimpleDateFormat sdf = new SimpleDateFormat(format);
Date date = sdf.parse(dateStr);
return date.getTime();
}
So considering start time, when I run from localhost, For August 1, I got
result = 1375295400000, which means Thu Aug 01 2013 00:00:00 GMT+0530
(India Standard Time). (So I understand there is a 5 hrs 30mins
milliseconds to be subtracted from the UTC.)
Expected similar UTC to be saved when run from server (US), but it saved
1375336800000 which means Thu Aug 01 2013 11:30:00 GMT+0530 (India
Standard Time) so UTC time is different and there is 11:30 hours flaw in
addition to 5:30 hrs flaw.
Did not use the following code on the server but I expect similar results -
Calendar calendar = Calendar.getInstance();
String[] arr = dateStr.split("/");
calendar.set(new Integer(arr[2]), new Integer(arr[0]), new Integer(
arr[1]));
return calendar.getTime();
Kindly help me resolve this problem. Also while doing comparison at
runtime I have to use new Date() so how should that be?