I have not played any of Path of Fire content except for the beta, and I've heard that the new maps lacked "meta events". It turns out that there are some timed events that could be added to site, below are player reported timings of some events. I've added to the timeline the "Casino Blitz" and "Buried Treasure" event as confirmed by some players, if these are incorrect, or if you know of more scheduled events that can be added to the site then please reply to this thread.
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Edit 2017-10-15: Serpents' Ire has been moved from the timeline to the Chains page, due to a sliding schedule (1 hour after reset, 90 minutes cycle); you can still find Serpents' Ire on the world boss row on the timeline by hovering over the timeline. On the chains page or tile mode, you may now subscribe to Serpents' Ire for alarms by clicking its time.