Is there a way to make Ical send notifications to Invitees on a certain day?

I am president of My 4-H Club and I need a way to keep 200 members informed about all of the upcomming events. At the beginning of the year, I add all of the events for the year in ical, and invite the group to each event. The problem is that ical sends out the reminder email inviting the members to the event the day that I Create the Event (Which sometimes is 6 months before the event). Is there a way to scedule the ical event reminder? If I create the event today, I do not want the members to receive the invite until one or two days before the event.