My wedding is on July 2014 and I already have 61 people confirmed. They put down a room deposit so if they back out 3 months before the wedding, they loose their deposit, not me. I ordered save the date magnets and will send them soon to keep people excited about our wedding. The hotel is usually sold out for the July 4th weekend so I need to have everyone fully booked 4-6 months before my wedding. So I think if you send at least save the date's now, people will have time to plan accordingly, check out flights, straighten things out with their employer and such. It will also give you more time to budget accordingly.