code: public static Date getTimestampFromLong(long timestamp)
     {
        TimeZone tz = TimeZone.getDefault();
        Date result = new Date(timestamp - tz.getRawOffset());
  
        if (tz.inDaylightTime(result) == true)
        {
           int savings;
  
           if (HAS_DST_SAVINGS == true)
           {
              savings = tz.getDSTSavings();
           }
           else
           {
              savings = DEFAULT_DST_SAVINGS;
           }
  
           result = new Date(result.getTime() - savings);
        }
        return (result);
     }
docs: Creates a timestamp from the equivalent long value. This conversion
  takes account of the time zone and any daylight savings time.
  
  @param timestamp timestamp expressed as a long integer
  @return new Date instance