The TSAC site offers the following RSS feeds:
Also available as ical feed: https://tsac.alpenclub.nl/agenda/ical
What is RSS and what can I do with it?
To be kept informed about new content on a website, you can of course check all pages daily. On a site as the TSAC with hundreds of pages it is not feasible to do this by hand. And that's excactly where RSS is for. Let software scan all the pages and be notified of the changes only. Don't ever miss that news item or that newly uploaded photo album!
Almost all blogs and news site offer one or more RSS feeds. Therefore, you can check multiple website from a single location.
There are a number of RSS readers. There are programs for PC or laptop, apps for your phone and websites like Feedly. Google on "RSS client" and you will find plenty.
If you prefer to get the changes sent to you by e-mail, then you can subscribe to free RSS to e-mail services like Blogtrottr.
The RSS feeds on the TSAC site are always fresh. However, it can be that your RSS client shows you information that is a couple of hours old, because it crawls the website only each couple of hours.