RailsのマイグレーションでSeedデータが入らない

いつもお世話になっております。Daiと申します。

新しくテーブルを作成して、開発用のSeedデータを作り、migrateしたのですがエラーが起こりSeedデータが入らないです。どなたか解決策をご存知でしたらご教授お願いいたします。

Seedデータのファイル

Ruby
1body =
2   "内容"
3
40.upto(9) do |idx|
5    Hoge.create(
6        title: "hoge#{idx}",
7        body: body,
8        released_at: 8.days.ago.advance(days: idx),
9        expired_at: 2.days.advance(days: idx),
10        member_only: (idx % 3 == 0)
11    )
12end

エラー内容

$ rails db:seed
Creating hoges...
rails aborted!
NoMethodError: undefined method `advance' for 172800:Integer
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/duration.rb:232:in `method_missing'
/home/ec2-user/environment/gruppe/db/seeds/development/groups.rb:9:in `block in <top (required)>'
/home/ec2-user/environment/gruppe/db/seeds/development/groups.rb:4:in `upto'
/home/ec2-user/environment/gruppe/db/seeds/development/groups.rb:4:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `block in require'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:259:in `load_dependency'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
/home/ec2-user/environment/gruppe/db/seeds.rb:6:in `block in <top (required)>'
/home/ec2-user/environment/gruppe/db/seeds.rb:2:in `each'
/home/ec2-user/environment/gruppe/db/seeds.rb:2:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:287:in `load'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:287:in `block in load'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:259:in `load_dependency'
/usr/local/rvm/gems/ruby-2.4.1/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:287:in `load'
/usr/local/rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/engine.rb:549:in `load_seed'
/usr/local/rvm/gems/ruby-2.4.1/gems/activerecord-5.0.6/lib/active_record/tasks/database_tasks.rb:270:in `load_seed'
/usr/local/rvm/gems/ruby-2.4.1/gems/activerecord-5.0.6/lib/active_record/railties/databases.rake:184:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands/rake_proxy.rb:14:in `block in run_rake_task'
/usr/local/rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands/rake_proxy.rb:11:in `run_rake_task'
/usr/local/rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:51:in `run_command!'
/usr/local/rvm/gems/ruby-2.4.1/gems/railties-5.0.6/lib/rails/commands.rb:18:in `<top (required)>'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Tasks: TOP => db:seed
(See full trace by running task with --trace)

よろしくお願いします。