Niantic Support just shared a ‘Spiritomb alert’ on their official Twitter account before the Special Research Spiritomb goes away.
The alert reads:
Hi Trainers, don’t forget that Professor Willow needs your help to get to the bottom of the strange happenings in his lab! Be sure to talk to him before 1:00 pm (PDT) on November 1 before this limited-time Special Research goes away.
Some Trainers are confused and think that Spiritomb will leave on November 1. Let’s make this clear – Those who haven’t started with the Special Research should start before that time (November 1 at 1:00 PM PDT) if they want to catch Spiritomb. If you don’t start with the tasks until that time (November 1 at 1:00 PM PDT) then you will lose the chance to catch Spiritomb.
Talk to your friends who haven’t started yet and remind them to do so until the given time.