rrule
JavaScript library for working with recurrence rules for calendar dates.
ics
iCal (ics) file generator
ical.js
Javascript parser for ics (rfc5545) and vcard (rfc6350) data
timezones-ical-library
Easy direct access to the most recent official timezone information for iCalendar files via JavaScript
ical-generator
ical-generator is a small piece of code which generates ical calendar files