With a JSON-RPC server, client services via a myriad of language options, including bash+nc, ruby, and java, send messages that ultimately are used to create events in Google Calendar. These events may be used to easily identify when an event (a Cron Job, batch script, etc...) started, stopped, and what its exit status was. For an organization that relies heavily upon the success, timeliness, and regularlity of many many batch jobs, a tool like that can prove to be a real benefit to systems administrators.
Gemfile gem 'CalMon', '~> 0.0.5'
install gem install CalMon