I like this software very much. And I have a suggestion. A calendar for user define which is a public holiday. And then add a option for use the different alert actions.
Example: In working-day then send mail to Adm. In holiday then send message to the pager.
Interesting idea. Now you can use different actions depending on time or day of week (using "Time restriction" options in the Action Properties dialog). But I did not think about holidays. I have added your request into our "to do" list. Thanks