Look for these lines. In this case I've made the site events out to 50 days and personal events to 28.
$eventSql = "SELECT eid, title, url, datestart, dateend FROM WHERE dateend >= NOW() AND "
. "(TO_DAYS(datestart) - TO_DAYS(NOW()) < 50) ORDER BY datestart, dateend";
$personaleventsql = "SELECT eid, title, url, datestart, dateend FROM WHERE uid = AND dateen$
. "(TO_DAYS(datestart) - TO_DAYS(NOW()) < 28) ORDER BY datestart, dateend";