Hello,

Thank you for your message.

You can change the default corporate site CSS for Event calendar if you edit the ~\App_Themes\CorporateSite\Default.skin file.

Another option is to override those classes. Are you familiar with Firebug addon for Firefox? You can easily check the source code along with classes generated on the page and then you can style it using the CSS inheritance.

Let me know for further assistance.

Kind regards,
Richard Sustek