A network management apparatus that executes a registered task at a specified time on a device connected thereto via a network includes a determination unit configured to determine whether a registered task related to a new task exists, and a registration unit configured to, if the determination unit determines that the registered task related to the new task exists, specify a time when the new task can be executed, to accept a registration of the new task to be executed at the time, and not to accept the registration of the new task to be executed at other than the time.