Simple generation timestamp

Anon

Quick question: How can I create a self-generating error404 message which says when the error occured? I need it to display something like:

Error404 (File not found)

Sorry, but your file cannot be served.
Contact the sysadmin for help.

Error occurred at: (page generation time/date)

I don't need anything fancy, just the date, time, and possibly the page the user was trying to reach.

Anon

The page itself is easy to write in PHP. The trick is getting the
webserver to display <i>your</i> 404 page instead of the default
one. If you're using Apache, you can add the following line to
httpd.conf:

  ErrorDocument 404 /404.php

Even if you don't "own" the server, you can still active a custom
error page using .htaccess by adding the same line above to
your .htaccess file. Now, if your server isn't configured to look
at .htaccess either, then you're out of luck.

Anon

Also, in your 404.php script, $REDIRECT_URL will give you the
name of the non-existing page the user tried to retrieve.

Anon

I'm just learning PHP (with a since oudated 3.0.16/4.0b1 manual), so I don't have a good feel for the general structure of a document like this. Any simple examples?