Saying "I do" is only the beginning to wedding planning. The next step for many couples is the Save the Date Cards. This pre-invitation mailing officially announces your wedding date and lets guests know that they will, in fact, be invited to the celebration.
Think of your Save the Date cards as a preliminary invitation to your wedding. They should be sent at least four months before the wedding date. Your wedding invitations should follow about two months later.
If you are asking guests to travel a great distance, take time off work, or travel during peak seasons, the sooner you can let them know the better! In these circumstances, it’s not uncommon to send Save the Date announcements as much as twelve months in advance.
Save the Date cards just to the people that you want to come to your wedding. Even if you've already received confirmations from certain guests, you still need to send them a save-the-date (bridesmaids, siblings, and parents). But remember: Only send to those that you definitely want to attend. Once these are in the mail, there's really no turning back.