19.50 Obviously we all knew the date... http://www.doctorwho.tv/whats-new/article/transmission-time-confirmed-for-the-day-of-the-doctor
When will it air on BBC America, though? Here in the States, beginning a show ten minutes before the hour just isn't done.
They'll probably make a Doctor Day of it, like they do at Christmas, so, I imagine they can work it out with Retrospectives or show the overlong Specials. It is supposed to be simulcast