There's no timetable. Most things only last for a few days, sometimes it'll be a few weeks at most, but usually it's not that long. The stuff like when people can't lie, or speak in poetry, or get turned into their younger selves - that's usually only a few days. The bunnies and geese stuck around longer. None of them seem connected to each other, but maybe the DOA know more about it. My friend's dad is one of the people who run the DOA - Noctis. You could talk to him maybe.
A lot of people are working on it and have notes and stuff, you can probably read all of what they have too if you want.