Sept 15, 1842: The date of the first two Times and Seasons articles that have misled some LDS scholars into believing the Book of Mormon took place in Mesoamerica.
Sept 22, 1827: The date Joseph Smith obtained the plates from Moroni.
Oct 1, 1842: The date of the third Times and Seasons article that claimed Zarahemla as in Quirigua, leading some LDS scholars on a wild-goose chase through Central America.
To commemorate Sept 15, I posted a comment about the RAGS translation of the Book of Mormon, the one used by Mesoamericanists instead of Joseph's translation. In the last few days, I've seen additional variations on the RAGS translation, in which Mesoamerican proponents substitute their own words and phrases to "fix" what Joseph translated so it will "fit" into a Mesoamerican setting. If you don't know what I'm referring to, take a look at John Sorenson's book, Mormon's Codex, Brant Gardner's book Traditions of the Fathers, or pretty much anything published about Book of Mormon geography by FARMS/Maxwell Institute, the Interpreter, or FairMormon (Fairlds). None of these stick to Joseph Smith's translation. If they did, they wouldn't be looking in Mesoamerica.
To commemorate Sept 22, I'm going to release a short book on Amazon/Kindle titled Letter VII: the letter every Latter-day Saint needs to read. There will be a Spanish version as well. I hope that every member of the Church will read this before beginning the Book of Mormon course of study in 2016.
To commemorate Oct 1, I'm going to release a short book on Amazon/Kindle titled The Treason of the Geographers: excerpts from LDS scholars on the Book of Mormon. That one will feature some of the "greatest hits" from FARMS/Maxwell Institute, The Interpreter, FairMormon (FairLDS), BMAF, and other works published by the Mesoamericanists.
What are you doing to commemorate these anniversaries?