You can do it with mod rewrite. This would go inside the .htaccess file of your first host (alwahshnt.net):
RewriteEngine On
RewriteCond %{TIME_SEC} ^[0-2][0-9]$
RewriteRule ^(.*)$ http://alwahshnt.heliohost.org/$1 [R=302,L]
Rewrite above redirects in seconds - if its 29 seconds into current minute, first site. After 29 seconds, heliohost site.