Add this at the the top of bittorrent.php if you dont have it next to the other config variables
PHP Code:
$h = date("H");
if ($h >= 01 && $h <= 06) //When to save some load.
$announce_interval = 60 * 60; //60 min update in announce - Night
else
$announce_interval = 60 * 30; // 30 min update in announce - Day