Note: If you need a calendar import job created, please contact Customer Support. The information below is strictly to provide the basics of the ics format that should be used. For more information please contact CS. If you already have a .ics file please provide that to CS in the ticket.
It is now possible to import events from iCalendar files in the admin area.  The following file extensions are allowed:
Currently we only supports a few elements from the specification. 
- X-WR-TIMEZONE - This is sometimes used by certain calendar softwares to denote the default timezone for all events that don't otherwise specify a timezone directly.  Example: "X-WR-TIMEZONE:America/Chicago"
- VTIMEZONE - Defines custom/existing timezones along with definitions for standard/daylight offsets.  Please see the RFC spec
- UID - [Required] a unique identifer for the event. Example: "UID:j1dpas32342dldddd3lvqcafjo@google.com"
- DTSTART - [Required] the start date and time of the event.  this will be converted to the timezone of the site
- DTEND - the end date and time of the event. this will be converted to the timezone of the site.  if the time portion is not specified, the event will be considered to have to end time
- RRULE - Not all combinations of recurrence rules will be supported here, but only those things which are provided in the schedule creation window in the event editor will likely work.  Currently, EXRULE is not supported.  The UNTIL portion of this element will be used to determine the end date of the event, if UNTIL is not present, the event will be considered to have no end date (i.e. "never ends").
 
 Supported properties for RRULE:
 - FREQ - daily/weekly/monthly/yearly
- INTERVAL - an integer defining how many to skip. so an interval of 1 would mean "every", 2 would mean "every other", and so on
- UNTIL - defined the end date/time of the recurrence rule (used as the event's stop date)
- COUNT - the number of occurrences to calculate
- BYMONTHDAY - the day of the month to use for a monthly/yearly schedule
- BYDAY - the day of the week (Sun - Sat)
- BYMONTH - the month to use for yearly schedules
 
- SUMMARY - used for the event title. if no title is defined, "(no title)" may be used in some cases
- DESCRIPTION - used for the content of the event
- LOCATION - used for the venue name field
- CONTACT - used for the contact name field
- URL - used for the website field
- STATUS - if this field is defined and has a value, anything other than "CONFIRMED" will cause the event to be set to not published (i.e. "unapproved")
- CATEGORIES - the comma-separated values here will be used as the event's section tags
- CREATED - Used as the creation time of the event
- GEO (in upcoming version 2.5.0) - the latitude/longitude coordinates of the event for use in spatial searches
Note:It may also be beneficial to validate the icalendar files before trying to import them.  There is a good validator located iCalendar.org.
- This is an example of an .ics export from Community / Calendar:
- BEGIN:VCALENDAR
- VERSION:2.0
- PRODID:-//TownNews.com//TNCMS Calendar v2.11.0//EN
- BEGIN:VEVENT
- UID:ad67195f-5e8a-5b2d-a092-01ef9d6bbebe-20131126T060000@jhaller.bloxcms.com
- SUMMARY:American Red Cross
- CATEGORIES:biztimes/events
- DTSTAMP:20131129T160801Z
- DTSTART;TZID=America/Chicago:20131126T060000
- DESCRIPTION:American Red Cross, 2:30 p.m., Galena High School, Galena, Ill.
- SEQUENCE:0
- STATUS:CONFIRMED
- END:VEVENT
- END:VCALENDAR