When using the iCal feed, it will only display 60 days' worth of data from the current day forward, but it is a "rolling" feed so it will update to include new events. It can take up to one (1) hour for the new events to sync into the calendar feed for the User on their Calendar. This can also be impacted by the Calendar client as well; for example, Google Cal can take up to 24 hours for the feed to sync with the new events.