The date for Community Race Day 1 for Need for Speed ProStreet has been announced by EA.
“On December 19th Castrol SYNTEC presents the first official Need for Speed ProStreet Community Race Day. Put your skills to the test against other Need for Speed ProStreet players across the globe. You’ll have the chance to play against developers of the game, win cool prizes, and unlock a special achievement only available during this Race Day! Be sure to join on December 19th to see if you can become the Castrol SYNTEC Race Day Street King!”
The achievement will reward you with 15 GamerScore and is unlikely to be achievable after this date. The achievement list suggests there will be a second Community Race Day soon after.