[php] convert php date to mysql format

This site has two pretty simple solutions - just check the code, I provided the descriptions in case you wanted them - saves you some clicks.

http://www.richardlord.net/blog/dates-in-php-and-mysql

1.One common solution is to store the dates in DATETIME fields and use PHPs date() and strtotime() functions to convert between PHP timestamps and MySQL DATETIMEs. The methods would be used as follows -

$mysqldate = date( 'Y-m-d H:i:s', $phpdate );
$phpdate = strtotime( $mysqldate );

2.Our second option is to let MySQL do the work. MySQL has functions we can use to convert the data at the point where we access the database. UNIX_TIMESTAMP will convert from DATETIME to PHP timestamp and FROM_UNIXTIME will convert from PHP timestamp to DATETIME. The methods are used within the SQL query. So we insert and update dates using queries like this -

$query = "UPDATE table SET
    datetimefield = FROM_UNIXTIME($phpdate)
    WHERE...";
$query = "SELECT UNIX_TIMESTAMP(datetimefield)
    FROM table WHERE...";