Cron jobs

Enable the daily or hourly cron addon, and Heroku will execute “rake cron” against your app, hourly for the hourly add-on, and once per 24 hour period with the daily add-on. You can use this to execute periodic background jobs by creating a file called lib/tasks/cron.rake and filling it in with your code. Remember the task is specified in Ruby code, so you can control the cron execution by checking the current hour, for instance:

task :cron => :environment do
 if Time.now.hour % 4 == 0 # run every four hours
   puts "Updating feed..."
   NewsFeed.update
   puts "done."
 end
 if Time.now.hour == 0 # run at midnight
   User.send_reminders
 end
end

To see recent results of your cron execution, type:

$ heroku logs:cron