PHP Datetime with MySQL datetime

I want to ask about change a datetime value of PHP with datetime value from MySQL data.
I have try to do this at PHP:
$sitgl = date('Y-m-d', strtotime(2012-01-12));
$sijam = date('H:i:s', strtotime(13:00:00));
$awal = $sitgl.' '.$sijam;
$awal2 = date('Y-m-d H:i:s', strtotime($awal));
$debrangkat = strtotime($awal2);
And I'm trying to convert same datetime at MySQL like this (convert it to seconds):
SELECT date_start_book, time_start_book, (TO_DAYS(CAST(date_start_book AS DATE))*86400) + TIME_TO_SEC(CAST(time_start_book AS TIME)) FROM `t_request_queue` WHERE `request_id` = '1301-0087'
which is date_start_book value is 2012-01-12 and time_start_book value is 13:00:00
My question is: why the PHP code return value : 1357970400 but the MySQL value return 63525214800 ?
what must I do to make both of value is same? Is strtotime() not return a seconds or why?

Answer:

Finally, I change the PHP to datetime and at query I'm using ADD_DAYS to add a date with a seconds then I compare it with the PHP datetime result.
So many thanks to all contributor.

http://stackoverflow.com/questions/14289836/php-datetime-with-mysql-datetime