converting time from BST to American timeZones CST MST EST PST

Question

I am converting time from GMT to different USA time-zones. For that, I have written a method which is returning the 1-hour prior time. if the time is 2:00 clock it's returning 1:00 clock

private static Date timeFormat(String timeZone) throws ParseException {
    SimpleDateFormat sdfDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    DateFormat gmtFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    gmtFormat.setTimeZone(TimeZone.getTimeZone(TimeZone.getDefault().getID()));
    Date date = null;
    try {
        date = gmtFormat.parse(sdfDate.format(new Date()));
        LOG.info("GMT format time and date ==>> "+date);
    } catch (ParseException e) {
        e.printStackTrace();
    }
    DateFormat pstFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    pstFormat.setTimeZone(TimeZone.getTimeZone(timeZone));
    String timedd = pstFormat.format(date);
    LOG.info("Return the new time based on timezone : "+pstFormat.format(date));
    return gmtFormat.parse(timedd);
}

Can anybody help me out what exactly is the issue, because a few months back the same method was working fine? Is it happening because of daylight saving time?

Answer 1

After so much of digging i have found that TimeZone won't give correct result on basis of time-zone

(EST, CST, MST, PST)

so in my method the param which i have passed as timeZone was coming as a

(EST, CST, MST, PST)

Instead of EST, CST, MST, PST i have passed US/Eastern US/Pacific US/Mountain US/Central, and it worked fine for me