In order for a Prenuptial Agreement to be valid under California Law, it must be done at least seven (7) days before the wedding occurs. The attorneys involved will need at least a few weeks (if not months) to guide their clients through the proper financial disclosures, draft the agreement, and iron out any issues which arise during negotiations.
I normally recommend clients who desire to have a Prenuptial Agreement begin the process approximately 4-6 months prior to their wedding date. As most people know, planning and coordinating a wedding is often a burdensome and stressful experience. Scrambling to finalize the Prenuptial Agreement is the last thing anyone wants to be concentrating on a week before their wedding date when this time should really be spent doing much more enjoyable things with family and friends.