There is no an exact date as of now. But few weeks ago RomanSINT said that the main sale should being started not later than March 2018.
Wouldn't that be too long, by then the energetic supporters would be weary.
This is the correct way of thinking. Additionally many ICOs appear and they have the greatest advertisement, thus investors go there. No ads — no one knows about SINTEZ. I insist that only the bigger hype can promote the project.
The idea is great, but it needs smart implementation.
Well, not much can be done until the team is willing to engage the support community.