This is the ceremony after meeting a shaman at the temple. I spoke to the shaman there and the quest advanced to say something like "wait for the ceremony". The shaman is sometimes there saying it will start later and sometimes is not there. Over four hours I have checked in regularly once leaving the character for over half an hour. I never remember waiting more than 5 minutes before. Possibly this is random very bad luck but I saw on general chat that at least one other player said it had been broken for him or her today. Server Skyfire character Tigaine.Since the shaman is standing there half of the time I know I am not on one of the wrong platforms but I have checked the other platforms every time just in case that triggers something.
As far as I know, it starts every 1h30 if somebody triggers it. If nobody triggered it recently, it starts when you show up.
I haven't had to wait very long. Are you wearing the necklace when you're waiting? I've been through it about 3 or 4 times now. Maybe a 10 min wait. The confusing bit for me was remembering to look for the flyer.