You can export your calendar in the iCal format, but doing the following:

1. Go to Preferences, Calendar.
2. Click Export to .ics.
3. Select the calendar to export. Click OK.
4. Select where to save the .ics file and click OK.

You can export your calendar in the iCal format, but doing the following:

1. Click on the Calendar tab.
2. On the left hand side of the screen click edit next to Calendar.
3. Click on the link next to Export to .ICS and you will prompted to save the .ICS file.

This Feature is not available in the Mobile version of Webmail.