Often, Save the Dates allow a more lighthearted tone than you want to go with for your invitations (without the invitation coming out tacky). These Save the Dates can be formal, fun and colorful, or both. When should you send out Save the Dates? The average American engagement is now 16 months; Invitations are only sent out 2-3 months in advance. Save the Dates just give your guests even more time to plan, especially those who are out of town.