P6 Calendars
Primavera P6 has three types of calendars: global, resource, and project.
A resource or project calendar may have a single GLOBAL calendar as its parent, but global calendars have no parent. This means that a P6 calendar may have at most two levels.
Open Plan supports a full calendar hierarchy (that is, the number of parents for a single calendar is not limited). Open Plan also supports separate calendar “files” at the project and resource levels. A “file” contains multiple calendars; however, Open Plan does not allow the creation, during import, of separate calendar files for the project and resource objects since allowing this would not permit assigning the same calendar to both an activity and a resource availability.
During import, Open Plan imports all calendars referenced from the main project(s) and any resources assigned to these projects. Open Plan also imports calendars that no longer exist on the main project but exist on the baseline project. Calendar hierarchy is preserved.
During export, calendar hierarchy is first flattened to no more than two levels. Calendars at the topmost level are typed as "Global" calendars while those at the second level are typed as "Project" calendars. Initially, the Project calendars are not assigned to any specific project. When a project first references a Project calendar, it is then assigned to that project. Any additional references to the same calendar by another project causes a “clone” of the original calendar to be created and assigned to any subsequent project(s). Likewise, when a resource references a Project calendar, the said Project calendar is cloned and typed as a "Resource" calendar. Subsequent resource references to the original Project calendar are redirected to the cloned Resource calendar.
As mentioned elsewhere, to avoid P6 calendars being renamed, do not use dot separators in the calendar name because Open Plan considers these separators as hierarchical delimiters. Also, be aware that using overly long names, especially for a calendar that has a parent, may result in truncation since the calendar ID field by default has a maximum length of 59 characters.