Convert Date String to/from ISO 8601 respecting UTC in Java

gistfile1.java

public static String toISO8601UTC(Date date) {
  TimeZone tz = TimeZone.getTimeZone("UTC");
  DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'");
  df.setTimeZone(tz);
  return df.format(date);
}

public static Date fromISO8601UTC(String dateStr) {
  TimeZone tz = TimeZone.getTimeZone("UTC");
  DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'");
  df.setTimeZone(tz);
  
  try {
    return df.parse(dateStr);
  } catch (ParseException e) {
    e.printStackTrace();
  }
  
  return null;
}