When Does The Loop Start/End
Happy Death Day’s original time loop was revealed to be triggered by a random firing of the Sisyphus Quantum Cooling Reactor on 12:01 AM, Monday, October 18th, 2017; an event we’ll name “Loop A.” “Loop A Prime” takes place under those same parameters, on the same date, just in a parallel dimension that makes up the majority of Happy Death Day 2U’s storyline. “Loop B” is the mini-loop we experience through Ryan Phan’s eyes, which takes place on Tuesday, October 19th, 2017; and also triggers a reset event as of 12:01 AM.
“Loop C” is the final loop, which we don’t know much about at this current moment. That’s the big sequel tease dangled at the end of Happy Death Day 2U, which sees Danielle Bouseman “voluntarily” dropped into a hell of her own. Of course, 12:01 AM is the best case scenario that ends the time loop, as the killer known as Babyface tends to end the lives of those involved in each version of the time loop we’ve seen so far.