Schedule continuous jobs via GitHub hook only. Schedule nightly and weekly jobs via cron job only. Experimental jobs may be scheduled on-demand with commit SHA or branch name as a parameter. Log in with GitHub credentials, click on a job, click "Build with Parameters", enter commit SHA or branch name, and click "Build". For pull requests, enter branch name "pr/1234/head" or "pr/1234/merge" for pull request #1234.