Compilation of Glitches v.100

When it spawns, iirc the time resets. Not when the old timer ends.
So, let's say it spawned @ 4:30 EST once I killed a mob to make room for kaccachi. It's timer ended for it to spawn @ 4:11 EST. I killed it @ 4:33 EST. Next time it will spawn is 4:30 EST.
I'm assuming this is what you meant by when? If not, this was a very vague question.

I'm not sure if they changed anything, but isnt there slight variation in the timing? The "standard" might be 24 hours, but it can range between say, 12-36...least that's what I remembered for stuff like mushmom, which was supposed to spawn in 45 minutes, but can go as low as 35 and up to an hour.