Now you can make calendar friendly files client-side. It outputs VCS files, so the files are compatible with all modern calendar software (Outlook, Apple Calendar, Google, etc.)

How To Use

Simply use the function...

download_vcs(filename, subject, description, location, begin, end);

begin and end need to be formatted in a way that is friendly to Date()

Dependencies

The tool uses 2 libraries from the following projects:

FileSaver.js (https://github.com/eligrey/FileSaver.js)
Blob.js (https://github.com/eligrey/Blob.js)

I've compressed them and included them into the source for the normal file. Other variations are available in the repo.

If you want IE to allow for either opening documents as well as saving documents, you can use my fork of FileSaver.js (https://github.com/nwcell/FileSaver.js)

Supported Browsers

Browser	Constructs as	Filenames	Size	Dependancies
Firefox 20+	Blob	Yes	800MiB/per	None
Firefox ≤ 19	data: URI	No		Blob.js
Chrome	Blob	Yes	345MiB/per	None
Chrome for Android v28+	Blob	Yes		None
IE 10+	Blob	Yes	600MiB/per	None
Opera Next	Blob	Yes		None
Opera < 15	data: URI	No		Blob.js
Safari ≤ 6	data: URI	No		Blob.js