The best day to make an appointment is today! We often hear sad brides say that they couldn't get in because their dress came in at the last minute. We were booked full by the time they called.
Our advice is to fill out an appointment request form when you know your wedding date, or as soon as you get an estimated date of arrival on a dress that you just ordered. If you are buying off of the rack, some girls set up appointments before they even go shopping or settle on a dress. We can always cancel an unnecessary appointment. What we can't do, is turn back time and make appointment slots available that have already been snagged by planning brides.
I hope this helps! :)