Change timestamp into another gmt+ timestamp
<p>Here goes my code but getting the same timestamp after changing the timezone.</p>

<pre><code>TimeZone timeZone = TimeZone.getTimeZone("GMT+11");
Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();

cal1.setTimeInMillis(Long.parseLong(classListDto.get(i)
    .getClassStartTime()) * THOUSAND);
cal2.setTimeInMillis(Long.parseLong(classListDto.get(i)
    .getClassEndTime()) * THOUSAND);
cal1.setTimeZone(timeZone);
cal2.setTimeZone(timeZone);

long startTimestamp = cal1.getTimeInMillis();
long endTimestamp = cal2.getTimeInMillis();
</code></pre>
