Amazon France and Amazon Canada both updated their The Sims 4 page with release dates. To make things confusing, these 2 release dates have 13 days of difference.
Amazon France says that The Sims 4 will be available on 15th of September, 2014.
Meanwhile, Amazon Canada‘s release date for The Sims 4 is 28th of September, 2014.
If we exclude the 13-day difference, there is a 99.99% chance that The Sims 4 will release some day in September.
See also The Sims 4 – Release Date Speculations for more info!
Thanks to SimCookie for the find!