What I did, which I liked more, because, it's less of a hassle.
I changed my $date variable (date to the test table in mysql) to a text field, and just have the insert code, insert my $datetime which is
$datetime = date("l F d, Y - H:i:s");
The same thing happened to me. With date/datetime in mysql, it will only post like: 2002-06-19 06:41:52
If you want the date, time, day, etc.. you need to use all the mysql options, date, time, day, year.. etc..
Now, since I probably made no sense.
This is my code, that inputs into the mysql dbase.
<?php
$date = date("l F d, Y - H:i:s");
include("mysqlinfo.php");
$result = "INSERT INTO personal_guestbook (date, name, email, url, content_body, topic)
VALUES ('$date', '$name', '$email', '$url', '$content_body', '$topic')";
$result=mysql_query($result);
?>
And with PhpMyAdmin, the $date field is a TEXT, not null.
You can see it for yourself at
http://www.mygaming.org/personal/guestbook.php
Sorry, if this didn't help, I'm somewhat new myself. :-p