The Jenkins Weekly Release Line delivers bug fixes and new features rapidly to users and plugin developers who need them. These releases are generally delivered on a weekly cadence, hence the name. For more conservative users, there is also a Long-Term Support (LTS) line.
The "weekly" release cadence is aspirational. Generally we target releasing Jenkins every week, but sometimes we do out-of-order releases. To get notifications about new releases, it is possible to subscribe to releases RSS feed.
Conditions for new releases of the Weekly Release Line:
Regular releases with all features, improvements, and bug fixes integrated since the last release.
Currently these releases happen on a weekly basis on Tuesdays.
Security releases for the Jenkins core (see the Jenkins Security page).
We coordinate Jenkins Weekly and LTS releases so that the vulnerabilities are fixed at the same time in all release lines. Jenkins security team sends notifications about upcoming security releases to Jenkins Security Advisory Channels.
Usually these releases happen on Wednesdays. If we release security updates on Wednesday, there will be no regular release the day before. Learn more about how we schedule security advisories.
Out-of-order releases in the case of major regressions and/or other reasons.
Unlike for the LTS line, there is no backporting process for the Weekly Release Line. Bug fixes, including fixes for regressions will be integrated towards the next release. While that release may be expedited (see out-of-order releases above), there won’t be patches for previous releases.
It is possible to switch between Jenkins Weekly and LTS release lines when needed. See the documentation here.