27th of August, 2019. Note that this is contingent on supermajority adoption by the Steem witnesses of the suggested upgrade, as is always the case with hardforks.

So this is just to tell us that after one month plus in the hands of the witnesses, that you are going to announce to all the businesses an implementation date that you have no real clues as to if it will happen or not, because the Supermajority has not spoken yet.

Instead of speculation, (on the witness acceptance), and a small attempt at coercion of the non-complying witnesses toward the super majority, it would have been much more useful to let us know where the witnesses stand on the issues, what their concerns are, and that this is why it is taking so long to determine if they are going to accept or deny the Hard Fork 21.

Contingent on supermajority--tells us, the users absolutely nothing. Announcing a date, basically giving the witnesses a Deadline smacks of coercion. I hope the witnesses, delay the HF21 well beyond your announced date. (There are several parts of HF21, that I think are bad), and that is why I hope they delay it, so they can properly do their due diligence and to not bow to pressures from any group, side, or organization.