https://pokemongolive.com/en/post/moltresday2018sep/
"If certain areas of the world can meet the challenge requirements,they’ll unlock bonus Stardust for catching Pokémon and hatching Eggs—including a guaranteed 3,000 Stardust for every raid—starting September 3 at 1:00 P.M. PDT. Also, until September 10 at 1:00 P.M. PDT, Trainers can unlock a bonus to earn Star Pieces that will last for one hour!"