Abstract: When an adjustment partner performing access is an intermediate inputter, a time/date adjustment apparatus extracts third candidate time/dates that are available time/dates of a participant on a side of an adjustment initiator satisfying an adjustment condition of the adjustment initiator and are within a range of second candidate time/dates, and determines fourth candidate time/dates based on an input of the intermediate inputter on the extracted third candidate time/dates, and when the adjustment partner performing access is a final inputter, the time/date adjustment apparatus extracts fifth candidate time/dates that are available time/dates of the participant on the side of the adjustment initiator satisfying the adjustment condition of the adjustment initiator and are within a common range of all of the fourth candidate time/dates, and determines an assembly time/date out of the fifth candidate time/dates based on selection of the final inputter.

Abstract: A time/date adjustment apparatus includes an authentication unit configured to perform authentication processing with an external system managing schedule information of a belonging member belonging to an organization being a member of the time/date adjustment apparatus and a site to be used by the belonging member. The authentication unit performs first authentication processing with the external system, by using an administrator privilege account of the external system. After the first authentication processing succeeds, the authentication unit acquires belonging member information and site information from the external system by using the administrator privilege account, the belonging member information and the site information including information that is not allowed to be acquired using an account not having an administrator privilege of the external system.