Saving timestamp in mysql table using php

Question

I have a field in a MySQL table which has a timestamp data type. I am saving data into that table. But when I pass the timestamp (1299762201428) to

Answer 1

$created_date = date("Y-m-d H:i:s");
$sql = "INSERT INTO $tbl_name(created_date)VALUES('$created_date')";
$result = mysql_query($sql);