In a typical office, there are many recurring tasks. If the recurrence pattern can be determined, then this pattern can be used to forecast which task might occur or provide guidance for a coworker who takes on the given responsibilities. A calendaring system is a popular tool for task enumeration. However, the existing major implementations are not capable of handling fluctuation cycle in the recurrences or the relationships between the tasks, and thus these systems do not give the user any analytical perspective on the tasks. Therefore, this paper proposes a new calendaring system that can handle changes in the recurrences and display the relationships between tasks. Three new concepts, Task, Mission, and Job are introduced to describe the relationships between the tasks. Interoperability with the existing systems is also described.