Your hub / portal can be setup so that all listings, events , blogs etc can be shared to all members and viewable on the members personal calendar. The member has the option to turn this on / off. This could enable a hub to share information of listings, events, blogs via the personal calendar. All members will have access to this information if they so desire.

The members personal diary can be multi functional displaying preset dates, events with detailed links, plus their personal dates only visible on the members profile.