Some event web pages have links to let you add the event to your calendar. They use a variety of techniques to do so.
When I click on, for example, Great American Sing-along, which seems related to the ActiveDataExchange product, using Chrome, it just offers to download a file "adecalendar.ics". Firefox offers the same option, and also offers to let me open the file with an app of my choosing, but only shows emacs as an option. And kitchen-sink though it may be, by default emacs doesn't seem to do any magic with .ics files ;)
I know that if I save it to a file, and go to https://www.google.com/calendar I can import a .ics file, but that involves a lot of frustrating steps.
So how can I just get a one- or two-click method of adding this to my google calendar?
Note that if the web site offers the calendar via a "webcal:" protocol, it is possible to configure a protocol handler so that gets passed off to the google calendar site, as documented at Google Calendar as default handler of webcal protocol for iCal/ICS files.
The only thing that we need to add an external calendar to Google Calendar is the address where the calendar itself resides. In this case, represented by the .ics file. Nevertheless, finding the proper address where the file is hosted may be certainly difficult, specially if it is coded in Javascript (as in this case) and not in a public URL.
Anyway. By Diving in the code of the page you provided in the question, I found that the .ics file can be reached in this address: http://events.colorado.edu/eventexport.aspx?Eid=14255&Iid=72564&Dt=O&fmt=I&invite=False&inviteemail=
So if you are interested in adding the appointment of this .ics file (and may be other appointments when the file is updated), you can import the file directly by Clicking the button next to "Other calendars" (the one with a small triangle pointing to downside) and choose "Add by URL" as we can see in the next screenshot:
You will be asked for the url, let's introduce the .ics file url and hit the "Add Calendar". Google Calendar will import the file and add it to your current appointments list as we can see in the next screenshot.
BTW The last appointment for that calendar seems to be dated for Sunday June 30 @ 16:00-18:00 Hrs.
Good luck!