Earlier this morning at 8am EST, Letter from the Producer LIVE Part VII was broadcasted live and as expected, Yoshi-P (Naoki Yoshida) answered one of most important questions about beta phase IV which is beta phase IV schedule. I directly quoted from square-enix forum as below:

Q1: When is Open Beta and Early Access?

A1: Beta Test phase 4 will run from August 17-19. Those who participated in the Beta Test phase 3 will be able to participate from August 16th. Early access will run from August 24th until the 26th with official service begins on August 27th, but the servers won’t go down after Early Access, so you’ll be able to play non-stop from August 24th.

In addition to beta phase IV schedule, Yoshi-P also answers other questions that we all are dreading to know and I think these two questions below are the most asked/sought in beta forum in addition to Open Beta and Early Access.

1) Will characters created in beta phase IV be carried over ? Yes

2) Will arcanist be available to play ? Yes

You can find full Q&A in square-enix forum.