Ok. Here's what I've done. This would be in a "filename.php" file on a server that supports PHP:
The swfobject stuff is what I use to include my swf movies. It works well, so I've included it. This code assumes that the swfobject.js file is in your directory.
$hour = date('g');
<!-- This is where your flash movie gets inserted. This content will be replaced -->
var so = new SWFObject("myswf.swf", "output", "550", "200", "8", "#ffffff");
so.addVariable("time", "<?php echo($hour)?>");