As alternative for the RSS feed, which you can add in your e-mail client, for instance, to see the calendar items directly, it is possible to subscribe to the TSAC calendar. Possible application to use are: Microsoft Outlook, Apple iCal and Google Calendar.
The address you have to use is
//tsac.alpenclub.nl/agenda/icalBy clicking on the link, your calendar application should ask you to add it. If this is not the case, or you are using Google Calendar, have a look at the pages below for more information.