Due to the powerful earthquake last year that struck Hokkaido, Japan, Moltres Day and all EX Raids on September 10 were canceled for Pokémon GO players in the region by Niantic, with no plans to postpone or reschedule. However, the developer eventually announced that this Moltres Raid Day would finally take place on October 19 from 11 a.m. to 2 p.m. JST. The Flame Pokémon was made available in Raid Battles for a three-hour period and knew the Flying-type move Sky Attack. Participants were also be able to encounter Shiny Moltres.
Source: Pokémon GO Japan @PokemonGOAppJP