Send invitations out eight weeks before (especially to out-of-town guests) your event. If you are planning a non-profit event or a special event at a convention or tradeshow, you may want to consider sending a save-the-date card in advance since people tend to book up quickly! Save the Dates can be sent as much as 3 months in advance. Holiday weekends are especially busy for everyone--so, if you're having a party to celebrate a special event (such as a wedding or Bat Mitzvah), be sure to get those invitations out early.