17.9 Is the start of the reference cards from Nvidia (USA). Asus also wanted to start around the same time.
Until the cards are offered for sale here, I would expect about a month later (nothing is officially known from Digitec yet).
In the end, the first few waves will be sold out immediately anyway, so I would reckon with the end of October/November until you get them.

I wrote to Digitech and they told me these will start selling on the 17.9.