Abstract: A system for transmission of data between a first device operated by a first user and a second device operated by a second user includes a database that receives a first set of data input by the first user and a second set of data input by the second user. In one embodiment, the second user can access at least a first portion of the first set of data from the database only after the second user authorizes the first user to access at least a first portion of the second set of data from the database. In another embodiment, the first set of data includes an immediate mode of access and/or one or more future modes of access of the first user which correlate to one or more specific time periods during which the future mode of access will become the immediate mode of access. Additionally, the first set of data can include a time-dependent schedule of the future mode of access of the first user.