Live scheduling, not a guess
Every countdown here comes straight from the server's own event schedule, not a fixed timer maintained on this page. An event without a confirmed next occurrence shows no countdown instead of a guessed one, and sorts to the bottom of the list.
Use the chips above the list to narrow it down to a single event type. The banner at the top always reflects the soonest event within whatever filter is currently active, not the whole schedule.
This page only tracks timing — for what each event actually requires and rewards, see the Event Guide, and for boss invasions specifically, the Invasions Guide.