To separately manage periods required for actual work of tasks and entire periods of the tasks.

A task management system includes an information processor and a management server connected with each other via a network. The information processor includes an input means 301 for inputting task information including execution scheduled periods of tasks, actual work scheduled periods showing periods required actual work in the execution scheduled periods, and information showing persons in charge of the tasks; and a transmission means 302 for transmitting the task information input from the input means. The management server includes a reception means 311 for receiving the task information transmitted by the transmission means of the information processor; a storage means 312 for storing the task information received by the reception means; and a calculation means 313 for calculating a total of actual work scheduled periods for each person in charge on the basis of the task information stored in the storage means 312.