A method of sharing a calendar between a plurality of users, the calendar being capable of holding one or more events. The method comprises providing the calendar to each of said plurality of users; allowing any of said plurality of users to add to the calendar any of a new event, a change to an event and a message relating to an event; and providing any new event, change to an event or message added by a user to the other users. A change to an event may comprise a change to at least one of a start time of the event, an end time of the event, a description of the event, a status of the event, whether the event is to be repeated and the persons attending the event.