To be able to easily share bookings between different calendars, it is possible to perform a sync with the google calendar. The Google Calendar can then sync with most systems.
How to:
While logged in, click one your user name.
You will find the button Sync with google at the bottom of the page. Follow the steps provided from Google.
The sync will last 1 month. The system will notify you when the sync is about to end and you re-activate the sync by clicking the link Sync with google again.
You find information about the active sync and date of expiration at the top of your Account settings.