Synchronization of the RAYNET Calendar with iCal is one-way. It means that activities can be modified only in the RAYNET calendar.
Click on your name in the upper right corner.
Click the iCalendar option.
Copy the calendar URL address.
In the calendar application click on File –> New Calendar Subscription.
Paste the copied URL address in URL calendar field. Click on Subscribe.
Name the calendar, pick colour and location (if you want to have the calendar available for your other devices, choose location iCloud). Finish procedure with OK.