I am depending upon this utility heavily these days; I appreciate its functionality and ease of use. Appointments are changing daily, sometimes more than once each day.

How about a "=Date()" or "=Now()" date and time stamp, drawing from the computer resource information, for the printed calendar? Example:
"Printed 5/13/2011 1300 hours" or "Printed 5/13/2011 1:00 PM"

Even if there is some coding problem with the various time zones, it would not matter, since the user would be able to discern the latest printout if more than one calendar is printed in a day.

Sure, I'll add a header to the print output which includes the time stamp.

Outstanding. Thank you!