Abstract: A system for booking a time period includes at least one provider arrangement on which a resource/service provider can indicate one or more available time periods within which they are able to provide a resource or service, and a plurality of user portals. Each user portal indicates which time periods of the service or resource provider/s are available to be booked on that portal by a user and facilitates booking of an available time period by a user. A synchronization and communications arrangement facilitates direct communication between the provider arrangement and each user portal in real time over a communication network to communicate the booking of an available time period on a the portal by a user to the provider arrangement and the other portals. This updates the available time periods on the provider arrangement and the user portals and removes each booked time period from the available time periods.