First of all, I didn't realize that PopTop Brent's warning was in this thread until this morning when I read all of his 66 posts. In that post, he also explained that it is important to save a newly created scenario with the editor turned on as this will reset the flag that determines whether or not the setup.evt will run. But you've already read that.
If I may ask, why are you trying to set the date back and is it that important?
Next thing, yes there was, and still is, some confusion about the editors. But you seem to have figured that out already too. Lord Corwin wrote his program because the editor provided by PopTop had very difficult to understand documentation and was not very user friendly. As far as I know, the debug keys that Brent referred to have never been included in the game's editor. Recently, when someone asked about resetting the date, I posted that I thought it could be done. I was quickly corrected.
And lastly, about reading all the old stuff before asking a question. There are some regulars here that get a bit testy when the same questions come up over and over. And it is always good to read a question that at least sounds like the asker has tried to find an answer on their own. But, there are almost 5200 topics and 96,000 posts on this forum! By the time anyone could read all that they'd be too old to play the game. And the search feature here isn't always the most efficient way of finding information either. So I try to be as tolerant as possible of the newbies. After all, we all were newbies here at some time. Even me.
I think that any question that is intelligently written at least deserves a cordial reply.