Shift is one of the key elements in defining project and resource calendars. Two additional key elements that are required to define the project and resource calendars are:
Schedule Exceptions: These are dates or periods that override the regular workday patterns and shifts of a calendar. They can be used to define holidays, vacations, or other special events that affect the availability of resources or projects.
Workday Patterns: These are patterns of working and nonworking days that repeat over a period of time. They can be used to define the standard working days and hours for a calendar. Time off, expenditure type, and accounting calendar are not key elements in defining project and resource calendars. Time off is an attribute of a resource assignment that reduces the availability of a resource. Expenditure type is a classification of costs that determines how they are processed and accounted. Accounting calendar is a calendar that defines the accounting periods and dates for transactions. https://docs.oracle.com/en/cloud/saas/project-portfolio-management/20c/oapfm/manage-project-resources.html#OAPFM2356131