有了它,你有schedule.rb文件,它指定何时应该完成某些事情,包括运行rake任务,执行方法,甚至执行任意shell命令：

示例schedule.rb文件,从Whenever自述文件中无耻地复制：

every 3.hours do
  runner "MyModel.some_process"
  rake "my:rake:task"
  command "/usr/bin/my_great_command"
end

every 1.day,:at => '4:30 am' do
  runner "MyModel.task_to_run_at_four_thirty_in_the_morning"
end

every :hour do # Many shortcuts available: :hour,:day,:month,:year,:reboot
  runner "SomeModel.ladeeda"
end

every :sunday,:at => '12pm' do # Use any day of the week or :weekend,:weekday
  runner "Task.do_something_great"
end

every '0 0 27-31 * *' do
  command "echo 'you can use raw cron Syntax too'"
end

# run this task only on servers with the :app role in Capistrano
# see Capistrano roles section below
every :day,:at => '12:20am',:roles => [:app] do
  rake "app_server:task"
end

我使用Whenever执行许多任务,包括发送每日电子邮件.