when tommyinnit, technoblade and the rest of the rebels of lmanburg went to fight jsclatt,the name dawn of the 16th, was from a youtuber named the Sadist who named that event
1. The animation by SAD-ist in where Tommyinnit, WilburSoot, Technoblade, and co. take on Jschlatt and Dream. In the end, Wilbur ends up destroying L'manburg, and Technoblade spawns in 2 withers.
A reoccurring theme that on the 16th of any month, something bad will happen (mostly to Tommy) on the Dream SMP, starting with the Manburg Festival on October 16th. The occurrences (so far) are:
October 16 - Red Festival, Tubbo's second canon death November 16 - End of season 1, destruction of reclaimed L'manburg
December 16 - Tommy loses his things in exile, tries to claim his last canon life
January 16 - Tommy's discs are threatened, Crimson Egg grows ever stronger.
"Gosh, I can't believe what happened on Tommy's stream on the 16th!"
"What did the Curse of the 16th do to him this time?"
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).