About two months...

although some of the props and costumes may begin 3, 4 even 6 months ahead of time.

The costumes amaze me... they are "elaborate". And in the production dance, which this video is, every costume is distinct. Even if they look basically the same they are not.

This particular dance was very 'dark', to me anyway... hard to see the costumes in all their glory. - JamesJM