Dear 100 Hour Board,
How much time before they speak do speakers at General Conference have to have their talks prepared? Wasn't one of the talks that Elder Andersen quoted from that same session?
First of all, yes, Elder Andersen quoted lots of people who spoke during this same Conference. I don't remember if there was anyone who he quoted from the Sunday afternoon session, but if he did it could have just been from his notes; I don't know if they all have access to each other's talks before Conference starts. That said, I'm sure they can share their talks with each other if they want, I just doubt that it's some sort of requirement.
And from Elder Andersen's talk, it sounds like they can finish their talk just about whenever they want to. He mentioned that Elder Hales prepared a talk that he finished this past Friday evening (so the night before Conference started), while others had been finished for months. So it's probably a pretty individual thing, especially because you can't really put a timeline on when someone needs to receive revelation by. I have heard that the Church has a proofreader who reads the talks beforehand to take care of any grammatical issues, but as far as I know, they haven't made public what the specific timeline is for talks at General Conference.
If a reader knows anything else, feel free to leave a correction!
When I had recently returned from my mission, we had the privilege of having a member of the presidency of the seventy stay in our home. If I remember correctly (and this was over 3 years ago, so take it with a grain of salt), he said that the speaking assignments are usually finalized 3-4 months before conference, although the first presidency and quorum of the twelve obviously know that they will be speaking and can start 6 months in advance. In the basement of one of the buildings on temple square there is a mock pulpit where speakers can go to practice and refine their talks. Once the talk is completed, it goes to the proofreader that Alta mentioned, who also checks for doctrinal inconsistencies. I want to say the the first presidency and quorum of the twelve assist in the doctrinal check (again, not a great memory guys), giving them access to the talks beforehand.
Is this all true? Possibly. Could it be figments of my imagination? Also possible. But that's what I remember.
Since that may not be the answer you are looking for, allow me to leave you with a FUN FACT! Due to the broadcasting time constraints, speakers are given an extremely strict time limit (hence the practice area). Due to the high volume of talks that they give, most of the members of the first presidency and quorum of the twelve know their speaking speed in words per minute and can simply base their talks on that. That's a statistic that I would love to handy for myself.
Like Alta said, if any readers know anything else, please leave a correction!