https://github.com/javan/whenever
Add to gemfile
gem 'whenever'
bundle install
wheneverize .
Edit /config/schedule.rb
Write it on crontab
whenever --update-crontab my_awesome_app
To edit crontab
crontab -e
Update crontab
bundle exec whenever -i
Overwrite the whole crontab (be careful with this one!)
bundle exec whenever -w
current/bin/whenever -w