Creating an iCal Subscribable Calendar

I run a website that maintains a list of concert dates for an artist. I added some time back an export to iCal feature to the calendar - but now what I would really like to do is somehow make it so people can subscribe to the calendar - however I can't seem to find any information on how to do that.

Maybe I'm just not putting in the correct search terms. But if anyone knows how to make it so that people could subscribe, or give me a link to the information that I need to include, that would be great.

The event calendar in addition to the export to iCal file feature also has an RSS feed of all the dates.

 

I actually have a PHP script I use to pull data from a mySQL database and then it creates a proper .ics file. Found out that I can use a cron job to pipe the output to a file on the webserver every 30 minutes. Then I just use a link to point to the created file:

webcal://myserver.com/tour/calendar.ics

That seems to work perfectly and allows people to subscribe to the calendar.