Hey,
I recently got the black on black MVMT (Movement) watch and needed to set the date. There were no obvious solution on Google so I am writing this quick blog post.
It's much easier to do this if you take the watch off your wrist.
Solution:To change the date pull the crown on the right of the watch out. You will feel two clicks. The first is for the date. Set it to the first click and rotate crown towards you until you get to desired date.
Easy.
Hope this helped!