You will have to set up a custom view to see when
the "Created" date is.
Open the Calendar
Select the VIEW menu
Select CURRENT VIEW
Select DEFINE VIEWS
Highlight the BY CATEGORY VIEW and
click the COPY... button
Name the view something like (View Created date)
Click OK
Click FIELDS...
Now in the Available fields box select CREATED
and click the ADD button.
Move the field to the top of the list to have it be the first
field shown in your view.
Click OK
Click OK again
Click the APPLY VIEW button
Now you will see the date of the creation of the appointment.
Use the VIEW menu to change the view on this folder
as you need it.