shortcode for calendar importing?

Hi there,
I’m looking for a shortcode or something that I can put within existing calendar events that will allow someone to import the event into their own local calendar – iCal-type thing, I guess, but allowing for all sorts of Calendar importing, like Google, Outlook, etc.

My site has a calendaring system already, and it’s sort of adequate. But this is a feature that’s been asked for, so I’m wondering if there’s an easy way to implement it. It’s a performing arts organization, so it does make sense to allow folks to import a performance they’re interested in/have bought tickets for into their own calendaring program.

Thanks in advance.