[ozzy47]

Sure, you would need to create a plugin, ACP --> Plugins & Products --> Add New Plugin

Product: vBulletin
Hook Location: parse_templates
Execution Order: 5
Plugin PHP Code: Add the following;

if (date('F j') == 'April 1' AND THIS_SCRIPT == 'forumdisplay' AND in_array($foruminfo['forumid'], array(X,X,X)))
{
    $invert = '<style type="text/css">
    body {
          -webkit-transform: rotate(180deg);
          -moz-transform: rotate(180deg);
          -ms-transform: rotate(180deg);
          -o-transform: rotate(180deg);
          transform: rotate(180deg);
    }
    </style>
    
     <script>
       window.onload=toBottom;
    
       function toBottom() {
          window.scrollTo(0, document.body.scrollHeight);
       }
    </script> ';
$template_hook[headinclude_bottom_css] .= $invert;
}

Just change X,X,X to the forums you want this to happen on.

Also note, I wrote this to only happen on April 1, so if you want to test it, change the date.