Instructions to Subscribe to a Calendar

iCalendar (*.ics extension) is a popular file format used to distribute calendar information between different applications over the internet. The feeds URLs and instructions for using them in the calendar programs Microsoft Outlook 2007, Apple iCal, Mozilla Lightning and Google Calendar are below.

iCalendar URLs

Microsoft Outlook 2007/2010 Instructions

To subscribe to an iCalendar feed using Outlook:

1. From Tools menu select Account Settings
   (In 2010) Go to File and from the Account Settings... menu select Account Settings
2. Click on the Internet Calendars tab
3. Click the New button
4. Type or paste one of the calendar URLs above then click Add
   
   
5. In the Subscription Options dialog box, you can optionally rename the calendar. Make sure the box is checked in the Update Limit section.
   

Apple iCal Instructions

Mozilla Lightning Instructions

Lightning is a calendar plugin for the popular email client Mozilla Thunderbird. You can add an iCalendar feed as follows:

1. From the File menu in Thunderbird select New -> Calendar
2. Choose On the Network and click Next
3. Choose iCalendar format and paste or type the calendar URL from above in Location, then click Next
   
   
4. Optionally change the Name, Color and notification option then click Next then Finish
5. You can set the refresh frequency in Tools->Options->Lightning->General->Refresh Settings. Once or twice a day is sufficient.

Google Calendar Instructions

To subscribe to an iCalendar feed using Google Calendar:

1. In the left column, click on the Add link in the Other Calendars section.
   
2. From the menu select Add by URL.
3. Enter the feed URL in the dialog box then click Add Calendar.
   
4. There appears to me no way to manually set how often the calendar is refreshed.