Niantic has provided some details for the next Pokémon GO Community Day. Eevee will be the featured Pokémon. The timings of the community day event which will be held for 3 hours on both August 11 and 12, 2018 vary between regions:
The Asia-Pacific region: from 12 pm to 3 pm JST (UTC +9)
Europe, the Middle East, Africa, and India: from 9 am to 12 pm UTC (UTC +0)
The Americas and Greenland: from 11 am to 2 pm PST (UTC -8)
In addition, there will be 3-hour lures and 3x catch GO, as bonuses. The exclusive move is not yet known.