A shift combines several workhours related settings in a reusable entity. Besides the weekly working hours it can also hold information such as leaves and a time zone. It lets you create a work time calendar that can be used to limit the working time for resources or tasks.
Shifts have a global name space. All IDs must be unique within the shifts of the project.
An optional ID. If you ever want to reference this property, you must specify your own unique ID. If no ID is specified one will be automatically generated. These IDs may become visible in reports, but may change at any time. You may never rely on automatically generated IDs.