Hi,
Thanks for the quick reply but this is not what I was asking about. I want the post to be published on one day but linked to, in the calendar, from another day.
I want to be able to write about an upcoming event, publish the post, and associate another date to the post, from the calendar.

If I write about something now that is happening next week I want people to be able to read about it immediately, but I want the Calendar to display it, as an upcoming event, next week. I want to have a calendar that links to published posts and I think this quite a common situation on a school and other similar institutions.