Base Calendar: Serves as a template for project, resource and task calendars. Basic format includes Standard (8:00 a.m. to 5:00 p.m., one hour for lunch and off on weekends), 24-Hours and Night Shift. Adjust the base calendar if your company works less than 40 hours per week. Statutory holidays can also be defined in the Base Calendar.
Project Calendar: Documents the start and end dates in the project. In a manufacturing setting, you can set plant shutdowns on this calendar.
Resource Calendar: Captures non-working hours of a resource such as vacation and training. Use this calendar to indicate non-traditional working hours as well as night shifts.
Task Calendar: Helps adjust working times for non-human resources such as machines that must run overnight or 24 hours daily.
By setting these calendars correctly, project management software can calculate task durations correctly.