It depends on the type of dress you want. If you're looking for a made-to-order dress, it's cutting it close. Most made-to-order dresses take 6-9 months to create, so if you want a custom gown, it's best to start shopping at least 9 months before your wedding day. However, if you're open to buying a dress off the rack or from a sample sale, 6 months is a reasonable amount of time to find your dream dress.