Convert a Date String to Unix Timestamp

/**
 *
 * @param strDate: "yyyy-MM-dd hh:mm:ss"
 * @return unixtime, it´s the unix timestamp in long integer.
 *                0, in case of error.
 */
private long convertStringTotimestamp(String strDate){
    try{
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss z");
        Date parsedDate = dateFormat.parse(strDate);
        long unixTime = (long) parsedDate.getTime()/1000;
        return unixTime;
    }catch(Exception e){
        Print.logError((String)"Cannot convert Unit's UTC time to timestamp.");
        return 0;
    }
}