这有什么问题吗（用户模型，第 95 行）：
scope :by_recent, where('created_at BETWEEN ? AND ?', 1.month.ago, Time.now).order('created_at desc').
每当我启动 rails s 或 rails c 时，我都会得到：
/Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract_adapter.rb:202:in `rescue in log': PGError: ERROR: unrecognized time zone name: "UTC" (ActiveRecord::StatementInvalid)
在我的模型中评论该行会使错误消失。奇怪的。顺便说一句，我正在使用 postgres 9。通过 Homebrew (brew install posgtres) 安装。
此链接建议以下内容。但我不明白这个人建议的解决方案是什么......
MikZ：我想通了
当您覆盖访问器（使用表格列）时，rails 正在设置具有自动时区转换的访问器，您将遇到严重的问题
当离开rails默认（或设置时区）时，你会得到很好的结果，但如果你覆盖访问器，你会遇到严重的问题
所以：永远不要覆盖“时间”属性的访问器
完整错误：
/Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract_adapter.rb:202:in `rescue in log': PGError: ERROR: unrecognized time zone name: "UTC" (ActiveRecord::StatementInvalid)
: SET time zone 'UTC'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract_adapter.rb:194:in `log'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:496:in `execute'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:961:in `configure_connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:939:in `connect'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:228:in `initialize'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:25:in `new'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:25:in `postgresql_connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:228:in `new_connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in `checkout_new_connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:190:in `block (2 levels) in checkout'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:186:in `loop'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:186:in `block in checkout'
from /Users/Chris/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:185:in `checkout'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:93:in `connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:316:in `retrieve_connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:97:in `retrieve_connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:89:in `connection'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/base.rb:1330:in `replace_bind_variables'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/base.rb:1317:in `sanitize_sql_array'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/base.rb:1224:in `sanitize_sql_for_conditions'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/relation/query_methods.rb:206:in `build_where'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/relation/query_methods.rb:77:in `where'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activerecord-3.0.3/lib/active_record/base.rb:441:in `where'
from /Users/Chris/Sites/site_name/app/models/user.rb:95:in `<class:User>'
from /Users/Chris/Sites/site_name/app/models/user.rb:1:in `<top (required)>'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:454:in `load'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:454:in `block in load_file'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:596:in `new_constants_in'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:453:in `load_file'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:340:in `require_or_load'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:491:in `load_missing_constant'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:183:in `block in const_missing'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:181:in `each'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:181:in `const_missing'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/inflector/methods.rb:124:in `block in constantize'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/inflector/methods.rb:123:in `each'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/inflector/methods.rb:123:in `constantize'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:528:in `block in <class:Reference>'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:538:in `yield'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:538:in `default'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:538:in `get'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/bundler/gems/devise-bbaaefa995c3/lib/devise/mapping.rb:76:in `to'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/bundler/gems/devise-bbaaefa995c3/lib/devise/rails/routes.rb:164:in `block in devise_for'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/bundler/gems/devise-bbaaefa995c3/lib/devise/rails/routes.rb:160:in `each'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/bundler/gems/devise-bbaaefa995c3/lib/devise/rails/routes.rb:160:in `devise_for'
from /Users/Chris/Sites/site_name/config/routes.rb:75:in `block in <top (required)>'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/actionpack-3.0.3/lib/action_dispatch/routing/route_set.rb:233:in `instance_exec'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/actionpack-3.0.3/lib/action_dispatch/routing/route_set.rb:233:in `draw'
from /Users/Chris/Sites/site_name/config/routes.rb:1:in `<top (required)>'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:235:in `load'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:235:in `block in load'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `block in load_dependency'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:596:in `new_constants_in'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `load_dependency'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:235:in `load'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:127:in `block in reload_routes!'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:127:in `each'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:127:in `reload_routes!'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:120:in `block in routes_reloader'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/file_update_checker.rb:32:in `call'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/file_update_checker.rb:32:in `execute_if_updated'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application/finisher.rb:51:in `block (2 levels) in <module:Finisher>'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application/finisher.rb:52:in `call'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application/finisher.rb:52:in `block in <module:Finisher>'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/initializable.rb:25:in `instance_exec'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/initializable.rb:25:in `run'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/initializable.rb:50:in `block in run_initializers'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/initializable.rb:49:in `each'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/initializable.rb:49:in `run_initializers'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:134:in `initialize!'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:77:in `method_missing'
from /Users/Chris/Sites/site_name/config/environment.rb:5:in `<top (required)>'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `block in require'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `block in load_dependency'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:596:in `new_constants_in'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `load_dependency'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:239:in `require'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:103:in `require_environment!'
from /Users/Chris/.rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/commands.rb:22:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
编辑：
实际上，问题与这个问题有关。我也从 macports 搬到了自制软件。在使用自制软件安装 postgres 之前，我需要删除 /opt/local 吗？
其次，我可以执行 rake db:drop:all 和 rake db:create，但不能执行 rake db:migrate。我得到：
rake aborted!
PGError: ERROR: unrecognized time zone name: "UTC"
: SET time zone 'UTC'