DateTimeZoneConversion.java

public static Date localToGMT() {
    Date date = new Date();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
    sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
    Date gmt = new Date(sdf.format(date));
    return gmt;
}

public static Date gmttoLocalDate(Date date) {

    String timeZone = Calendar.getInstance().getTimeZone().getID();
    Date local = new Date(date.getTime() + TimeZone.getTimeZone(timeZone).getOffset(date.getTime()));
    return local
}

// You can use DateFormat.parse(String date) instead of new Date(String date) as it is deprecated.