Changing created_at for seed.rb data

I'm using seeds.rb to load some dummy data into my project as I develop it.

I'd like to use a random created_at date for my records, but the created_at date is always set to Time.now on create.

  #seeds.rb
  Project.cr开发者_如何学Goeate :name => 'Dummy Project',
                 :created_at => Date.today - rand(10).days

project = Project.create(:name => 'Dummy Project')
project.created_at = (rand*10).days.ago
project.save

The created_at can't be defined during creation. It can only be changed afterwards.

This works:

p = Project.create :name => 'Dummy Project'
p.update_attribute :created_at, (rand*10).days.ago