Raw denim is best given a good six months before washing. The longer you can leave them, the better they will look. The indigo will have worn off in places where you make natural creases. When it comes to the big day, the indigo will fade to reveal the contrasts that give it the well worn jeans look.
If you wash them too early, the indigo will wash off uniformly so it will give an even, dark indigo colour which means the magic will have gone.
Like anything in life, there are no short cuts.