Accepted WListers from R1 were called a week before the deadline. All R1 and R2 acceptances came on deadline day.
There is a good chance that calls went out already. In last year's thread, not a single person was accepted on R3 deadline on GmatClub. 5 days after the deadline, a wave of dings came. I know of people that did get in off the waitlist after R3, and none was reported on this forum.
With that said, DYDT has a good point. The volume of calls tomorrow will be very low, so there is still a chance that calls will come in tomorrow as well.
the good news (or bad news) is that the majority of us will finally know one way or another in about a week.