Converting String in ISO8601 T-Z format to Date

A Date doesn't have any time zone. If you want to know what the string representation of the date is in the indian time zone, then use another SimpleDateFormat, with its timezone set to Indian Standard, and format the date with this new SimpleDateFormat.

EDIT: code sample:

String s = "2013-07-17T03:58:00.000Z";
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX");
Date d = formatter.parse(s);

System.out.println("Formatted Date in current time zone = " + formatter.format(d));

TimeZone tx=TimeZone.getTimeZone("Asia/Calcutta");
formatter.setTimeZone(tx);
System.out.println("Formatted date in IST = " + formatter.format(d));

Output (current time zone is Paris - GMT+2):

Formatted Date in current time zone = 2013-07-17T05:58:00.000+02
Formatted date in IST = 2013-07-17T09:28:00.000+05

Use calendar for timezones.

TimeZone tz = TimeZone.getTimeZone("Asia/Calcutta");
Calendar cal = Calendar.getInstance(tz);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'")
sdf.setCalendar(cal);
cal.setTime(sdf.parse("2013-07-17T03:58:00.000Z"));
Date date = cal.getTime();

For this however I'd recommend Joda Time as it has better functions for this situation. For JodaTime you can do something like this:

DateTimeFormatter dtf = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
DateTime dt = dtf.parseDateTime("2013-07-17T03:58:00.000Z");
Date date = dt.toDate();