Abstract: A download system capable of appropriately spreading loads on a server and on a transmission path, and further enhancing convenience in download of data. A reservation candidate acquirer of a communication terminal acquires from a software managing server reservation candidate information containing time information about time zones as candidates to which a reservation for download of an update file can be allocated. At the communication terminal a user selects a reserved time zone from the time zones corresponding to the time information included in the reservation candidate information, and the software managing server registers the reservation in the reserved time zone. Thereby, the reserved time zone can be selected from the candidate time zones transmitted by the software managing server and the candidate time zones are determined based on a reservation table set so as to spread loads on the software managing server and on the transmission path.