A window is a time in which deployments are allowed to a particular environment. Deployments occurring within the window are allowed to execute immediately (provided no other approval is configured), whereas, deployments outside of the window require the approval of a configured approver if the request is to be an exception to the window. Deployments outside of a window will be scheduled for the start of the next available window.
For details on Cron Expression Syntax see http://www.quartz-scheduler.org/api/2.2.1/org/quartz/CronExpression.html.
Starting in the 4.6 release, multiple Cron Expressions can be specified using semicolon as a delimeter. For example,
0 0 11 ? * *;0 0 12 ? * *
is equivalent to
0 0 11-12 ? * *
This allows for Cron Expressions that are scheduled to run on the 2nd and 4th Friday which is not normally possible with Quartz Cron.
A new Admin Screen was added to test expressions in the Administration Menu on the Admin Operations Screen.