A Calendar is a list, just like any other list; what is it that you want to
do?

One bad thing about the sharepoint calendar  list is that it doesn't create a new
item in the list for re-occuring events, instead it uses xml store in the sp
web-content database as a field so in order to access the re-occuring events  you
need to access it via the sp web services of the calendar list don't remember
exactly but Check out this link out I think it may help:

aspnetguru.wordpress.com/.../understanding-the-sharepoint-calendar\
-and-how-to-export-it-to-ical-format/

blogs.msdn.com/.../understanding-the-sharepoint\
-calendar-and-how-to-export-it-to-ical-format.aspx

social.msdn.microsoft.com/.../3df54\
418-abd5-4aa0-b2d6-1500fec9e06a/

my organization was working on a project to run a custom service to send out
notifications b/c there is nothing out of the box to do this but it got bump by
other projects good luck!!